diff --git a/compiler/rustc_ast_lowering/messages.ftl b/compiler/rustc_ast_lowering/messages.ftl
index 9ed93d481e773..0a7f75039f64d 100644
--- a/compiler/rustc_ast_lowering/messages.ftl
+++ b/compiler/rustc_ast_lowering/messages.ftl
@@ -167,11 +167,23 @@ ast_lowering_template_modifier = template modifier
 
 ast_lowering_this_not_async = this is not `async`
 
+ast_lowering_underscore_array_length_unstable =
+    using `_` for array lengths is unstable
+
 ast_lowering_underscore_expr_lhs_assign =
     in expressions, `_` can only be used on the left-hand side of an assignment
     .label = `_` not allowed here
 
+ast_lowering_unstable_inline_assembly = inline assembly is not stable yet on this architecture
+ast_lowering_unstable_inline_assembly_const_operands =
+    const operands for inline assembly are unstable
+ast_lowering_unstable_inline_assembly_label_operands =
+    label operands for inline assembly are unstable
+ast_lowering_unstable_may_unwind = the `may_unwind` option is unstable
+
 ast_lowering_use_angle_brackets = use angle brackets instead
+
+ast_lowering_yield = yield syntax is experimental
 ast_lowering_yield_in_closure =
     `yield` can only be used in `#[coroutine]` closures, or `gen` blocks
     .suggestion = use `#[coroutine]` to make this closure a coroutine
diff --git a/compiler/rustc_ast_lowering/src/asm.rs b/compiler/rustc_ast_lowering/src/asm.rs
index ea7b8c114f490..8acca78379b2e 100644
--- a/compiler/rustc_ast_lowering/src/asm.rs
+++ b/compiler/rustc_ast_lowering/src/asm.rs
@@ -19,10 +19,12 @@ use super::errors::{
     InvalidRegisterClass, RegisterClassOnlyClobber, RegisterConflict,
 };
 use super::LoweringContext;
-use crate::{ImplTraitContext, ImplTraitPosition, ParamMode, ResolverAstLoweringExt};
+use crate::{
+    fluent_generated as fluent, ImplTraitContext, ImplTraitPosition, ParamMode,
+    ResolverAstLoweringExt,
+};
 
 impl<'a, 'hir> LoweringContext<'a, 'hir> {
-    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     pub(crate) fn lower_inline_asm(
         &mut self,
         sp: Span,
@@ -52,7 +54,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     &self.tcx.sess,
                     sym::asm_experimental_arch,
                     sp,
-                    "inline assembly is not stable yet on this architecture",
+                    fluent::ast_lowering_unstable_inline_assembly,
                 )
                 .emit();
             }
@@ -64,8 +66,13 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             self.dcx().emit_err(AttSyntaxOnlyX86 { span: sp });
         }
         if asm.options.contains(InlineAsmOptions::MAY_UNWIND) && !self.tcx.features().asm_unwind {
-            feature_err(&self.tcx.sess, sym::asm_unwind, sp, "the `may_unwind` option is unstable")
-                .emit();
+            feature_err(
+                &self.tcx.sess,
+                sym::asm_unwind,
+                sp,
+                fluent::ast_lowering_unstable_may_unwind,
+            )
+            .emit();
         }
 
         let mut clobber_abis = FxIndexMap::default();
@@ -182,7 +189,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                                 sess,
                                 sym::asm_const,
                                 *op_sp,
-                                "const operands for inline assembly are unstable",
+                                fluent::ast_lowering_unstable_inline_assembly_const_operands,
                             )
                             .emit();
                         }
@@ -246,7 +253,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                                 sess,
                                 sym::asm_goto,
                                 *op_sp,
-                                "label operands for inline assembly are unstable",
+                                fluent::ast_lowering_unstable_inline_assembly_label_operands,
                             )
                             .emit();
                         }
diff --git a/compiler/rustc_ast_lowering/src/expr.rs b/compiler/rustc_ast_lowering/src/expr.rs
index 124fe6bd380d2..b5d8a547a8fb9 100644
--- a/compiler/rustc_ast_lowering/src/expr.rs
+++ b/compiler/rustc_ast_lowering/src/expr.rs
@@ -23,7 +23,7 @@ use super::{
     ImplTraitContext, LoweringContext, ParamMode, ParenthesizedGenericArgs, ResolverAstLoweringExt,
 };
 use crate::errors::YieldInClosure;
-use crate::{FnDeclKind, ImplTraitPosition};
+use crate::{fluent_generated, FnDeclKind, ImplTraitPosition};
 
 impl<'hir> LoweringContext<'_, 'hir> {
     fn lower_exprs(&mut self, exprs: &[AstP<Expr>]) -> &'hir [hir::Expr<'hir>] {
@@ -1540,7 +1540,6 @@ impl<'hir> LoweringContext<'_, 'hir> {
         }
     }
 
-    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn lower_expr_yield(&mut self, span: Span, opt_expr: Option<&Expr>) -> hir::ExprKind<'hir> {
         let yielded =
             opt_expr.as_ref().map(|x| self.lower_expr(x)).unwrap_or_else(|| self.expr_unit(span));
@@ -1575,7 +1574,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                         &self.tcx.sess,
                         sym::coroutines,
                         span,
-                        "yield syntax is experimental",
+                        fluent_generated::ast_lowering_yield,
                     )
                     .emit();
                 }
@@ -1587,7 +1586,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                         &self.tcx.sess,
                         sym::coroutines,
                         span,
-                        "yield syntax is experimental",
+                        fluent_generated::ast_lowering_yield,
                     )
                     .emit();
                 }
diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs
index 224787c335beb..81d17a9dec205 100644
--- a/compiler/rustc_ast_lowering/src/lib.rs
+++ b/compiler/rustc_ast_lowering/src/lib.rs
@@ -2326,7 +2326,6 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         self.expr_block(block)
     }
 
-    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn lower_array_length(&mut self, c: &AnonConst) -> hir::ArrayLen<'hir> {
         match c.value.kind {
             ExprKind::Underscore => {
@@ -2340,7 +2339,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                         &self.tcx.sess,
                         sym::generic_arg_infer,
                         c.value.span,
-                        "using `_` for array lengths is unstable",
+                        fluent_generated::ast_lowering_underscore_array_length_unstable,
                     )
                     .stash(c.value.span, StashKey::UnderscoreForArrayLengths);
                     hir::ArrayLen::Body(self.lower_anon_const_to_const_arg(c))
diff --git a/compiler/rustc_attr/messages.ftl b/compiler/rustc_attr/messages.ftl
index eb51e568f81a7..5d9ac23ec490e 100644
--- a/compiler/rustc_attr/messages.ftl
+++ b/compiler/rustc_attr/messages.ftl
@@ -104,6 +104,9 @@ attr_unknown_meta_item =
 attr_unknown_version_literal =
     unknown version literal format, assuming it refers to a future version
 
+attr_unstable_cfg_target_compact =
+    compact `cfg(target(..))` is experimental and subject to change
+
 attr_unsupported_literal_cfg_string =
     literal in `cfg` predicate value must be a string
 attr_unsupported_literal_deprecated_kv_pair =
diff --git a/compiler/rustc_attr/src/builtin.rs b/compiler/rustc_attr/src/builtin.rs
index cf86a6942da7e..d057dcfdf9d0c 100644
--- a/compiler/rustc_attr/src/builtin.rs
+++ b/compiler/rustc_attr/src/builtin.rs
@@ -20,6 +20,7 @@ use rustc_span::hygiene::Transparency;
 use rustc_span::symbol::{sym, Symbol};
 use rustc_span::Span;
 
+use crate::fluent_generated;
 use crate::session_diagnostics::{self, IncorrectReprFormatGenericCause};
 
 /// The version placeholder that recently stabilized features contain inside the
@@ -521,7 +522,6 @@ pub struct Condition {
 }
 
 /// Tests if a cfg-pattern matches the cfg set
-#[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
 pub fn cfg_matches(
     cfg: &ast::MetaItem,
     sess: &Session,
@@ -593,7 +593,6 @@ pub fn parse_version(s: Symbol) -> Option<RustcVersion> {
 
 /// Evaluate a cfg-like condition (with `any` and `all`), using `eval` to
 /// evaluate individual items.
-#[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
 pub fn eval_condition(
     cfg: &ast::MetaItem,
     sess: &Session,
@@ -680,7 +679,7 @@ pub fn eval_condition(
                             sess,
                             sym::cfg_target_compact,
                             cfg.span,
-                            "compact `cfg(target(..))` is experimental and subject to change",
+                            fluent_generated::attr_unstable_cfg_target_compact,
                         )
                         .emit();
                     }
diff --git a/compiler/rustc_borrowck/messages.ftl b/compiler/rustc_borrowck/messages.ftl
index c14a617eb91fe..edb25e12864bc 100644
--- a/compiler/rustc_borrowck/messages.ftl
+++ b/compiler/rustc_borrowck/messages.ftl
@@ -62,6 +62,9 @@ borrowck_could_not_normalize =
 borrowck_could_not_prove =
     could not prove `{$predicate}`
 
+borrowck_dereference_suggestion =
+    dereference the return value
+
 borrowck_func_take_self_moved_place =
     `{$func}` takes ownership of the receiver `self`, which moves {$place_name}
 
@@ -74,9 +77,24 @@ borrowck_higher_ranked_lifetime_error =
 borrowck_higher_ranked_subtype_error =
     higher-ranked subtype error
 
+borrowck_implicit_static =
+    this has an implicit `'static` lifetime requirement
+
+borrowck_implicit_static_introduced =
+    calling this method introduces the `impl`'s `'static` requirement
+
+borrowck_implicit_static_relax =
+    consider relaxing the implicit `'static` requirement
+
 borrowck_lifetime_constraints_error =
     lifetime may not live long enough
 
+borrowck_limitations_implies_static =
+    due to current limitations in the borrow checker, this implies a `'static` lifetime
+
+borrowck_move_closure_suggestion =
+    consider adding 'move' keyword before the nested closure
+
 borrowck_move_out_place_here =
     {$place} is moved here
 
@@ -163,6 +181,9 @@ borrowck_partial_var_move_by_use_in_coroutine =
         *[false] moved
     } due to use in coroutine
 
+borrowck_restrict_to_static =
+    consider restricting the type parameter to the `'static` lifetime
+
 borrowck_returned_async_block_escaped =
     returns an `async` block that contains a reference to a captured variable, which then escapes the closure body
 
diff --git a/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs b/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs
index 3590e12274ca6..d85959c9a291e 100644
--- a/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs
@@ -3,6 +3,8 @@
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
 
+use std::assert_matches::assert_matches;
+
 use rustc_errors::{Applicability, Diag};
 use rustc_hir as hir;
 use rustc_hir::intravisit::Visitor;
@@ -116,7 +118,7 @@ impl<'tcx> BorrowExplanation<'tcx> {
                     // path_span must be `Some` as otherwise the if condition is true
                     let path_span = path_span.unwrap();
                     // path_span is only present in the case of closure capture
-                    assert!(matches!(later_use_kind, LaterUseKind::ClosureCapture));
+                    assert_matches!(later_use_kind, LaterUseKind::ClosureCapture);
                     if !borrow_span.is_some_and(|sp| sp.overlaps(var_or_use_span)) {
                         let path_label = "used here by closure";
                         let capture_kind_label = message;
@@ -147,7 +149,7 @@ impl<'tcx> BorrowExplanation<'tcx> {
                     // path_span must be `Some` as otherwise the if condition is true
                     let path_span = path_span.unwrap();
                     // path_span is only present in the case of closure capture
-                    assert!(matches!(later_use_kind, LaterUseKind::ClosureCapture));
+                    assert_matches!(later_use_kind, LaterUseKind::ClosureCapture);
                     if borrow_span.map(|sp| !sp.overlaps(var_or_use_span)).unwrap_or(true) {
                         let path_label = "used here by closure";
                         let capture_kind_label = message;
diff --git a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
index 82df9760d8e7c..451e8bcb16da4 100644
--- a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
@@ -35,7 +35,7 @@ use crate::session_diagnostics::{
     LifetimeReturnCategoryErr, RequireStaticErr, VarHereDenote,
 };
 use crate::universal_regions::DefiningTy;
-use crate::{borrowck_errors, MirBorrowckCtxt};
+use crate::{borrowck_errors, fluent_generated as fluent, MirBorrowckCtxt};
 
 impl<'tcx> ConstraintDescription for ConstraintCategory<'tcx> {
     fn description(&self) -> &'static str {
@@ -198,7 +198,6 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
     // from higher-ranked trait bounds (HRTB). Try to locate span of the trait
     // and the span which bounded to the trait for adding 'static lifetime suggestion
     #[allow(rustc::diagnostic_outside_of_impl)]
-    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn suggest_static_lifetime_for_gat_from_hrtb(
         &self,
         diag: &mut Diag<'_>,
@@ -251,23 +250,28 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
         debug!(?hrtb_bounds);
 
         hrtb_bounds.iter().for_each(|bound| {
-            let Trait(PolyTraitRef { trait_ref, span: trait_span, .. }, _) = bound else { return; };
-            diag.span_note(
-                *trait_span,
-                "due to current limitations in the borrow checker, this implies a `'static` lifetime"
-            );
-            let Some(generics_fn) = hir.get_generics(self.body.source.def_id().expect_local()) else { return; };
-            let Def(_, trait_res_defid) = trait_ref.path.res else { return; };
+            let Trait(PolyTraitRef { trait_ref, span: trait_span, .. }, _) = bound else {
+                return;
+            };
+            diag.span_note(*trait_span, fluent::borrowck_limitations_implies_static);
+            let Some(generics_fn) = hir.get_generics(self.body.source.def_id().expect_local())
+            else {
+                return;
+            };
+            let Def(_, trait_res_defid) = trait_ref.path.res else {
+                return;
+            };
             debug!(?generics_fn);
             generics_fn.predicates.iter().for_each(|predicate| {
-                let BoundPredicate(
-                    WhereBoundPredicate {
-                        span: bounded_span,
-                        bounded_ty,
-                        bounds,
-                        ..
-                    }
-                ) = predicate else { return; };
+                let BoundPredicate(WhereBoundPredicate {
+                    span: bounded_span,
+                    bounded_ty,
+                    bounds,
+                    ..
+                }) = predicate
+                else {
+                    return;
+                };
                 bounds.iter().for_each(|bd| {
                     if let Trait(PolyTraitRef { trait_ref: tr_ref, .. }, _) = bd
                         && let Def(_, res_defid) = tr_ref.path.res
@@ -277,16 +281,17 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
                         && generics_fn.params
                             .iter()
                             .rfind(|param| param.def_id.to_def_id() == defid)
-                            .is_some() {
-                            suggestions.push((bounded_span.shrink_to_hi(), " + 'static".to_string()));
-                        }
+                            .is_some()
+                    {
+                        suggestions.push((bounded_span.shrink_to_hi(), " + 'static".to_string()));
+                    }
                 });
             });
         });
         if suggestions.len() > 0 {
             suggestions.dedup();
             diag.multipart_suggestion_verbose(
-                "consider restricting the type parameter to the `'static` lifetime",
+                fluent::borrowck_restrict_to_static,
                 suggestions,
                 Applicability::MaybeIncorrect,
             );
@@ -976,7 +981,6 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
     }
 
     #[allow(rustc::diagnostic_outside_of_impl)]
-    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     #[instrument(skip(self, err), level = "debug")]
     fn suggest_constrain_dyn_trait_in_impl(
         &self,
@@ -994,16 +998,12 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
             debug!("trait spans found: {:?}", traits);
             for span in &traits {
                 let mut multi_span: MultiSpan = vec![*span].into();
-                multi_span
-                    .push_span_label(*span, "this has an implicit `'static` lifetime requirement");
-                multi_span.push_span_label(
-                    ident.span,
-                    "calling this method introduces the `impl`'s `'static` requirement",
-                );
+                multi_span.push_span_label(*span, fluent::borrowck_implicit_static);
+                multi_span.push_span_label(ident.span, fluent::borrowck_implicit_static_introduced);
                 err.subdiagnostic(RequireStaticErr::UsedImpl { multi_span });
                 err.span_suggestion_verbose(
                     span.shrink_to_hi(),
-                    "consider relaxing the implicit `'static` requirement",
+                    fluent::borrowck_implicit_static_relax,
                     " + '_",
                     Applicability::MaybeIncorrect,
                 );
@@ -1045,7 +1045,6 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
     }
 
     #[allow(rustc::diagnostic_outside_of_impl)]
-    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     /// When encountering a lifetime error caused by the return type of a closure, check the
     /// corresponding trait bound and see if dereferencing the closure return value would satisfy
     /// them. If so, we produce a structured suggestion.
@@ -1166,7 +1165,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
         if ocx.select_all_or_error().is_empty() && count > 0 {
             diag.span_suggestion_verbose(
                 tcx.hir().body(*body).value.peel_blocks().span.shrink_to_lo(),
-                "dereference the return value",
+                fluent::borrowck_dereference_suggestion,
                 "*".repeat(count),
                 Applicability::MachineApplicable,
             );
@@ -1174,7 +1173,6 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
     }
 
     #[allow(rustc::diagnostic_outside_of_impl)]
-    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn suggest_move_on_borrowing_closure(&self, diag: &mut Diag<'_>) {
         let map = self.infcx.tcx.hir();
         let body = map.body_owned_by(self.mir_def_id());
@@ -1213,7 +1211,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
         if let Some(closure_span) = closure_span {
             diag.span_suggestion_verbose(
                 closure_span,
-                "consider adding 'move' keyword before the nested closure",
+                fluent::borrowck_move_closure_suggestion,
                 "move ",
                 Applicability::MaybeIncorrect,
             );
diff --git a/compiler/rustc_borrowck/src/type_check/canonical.rs b/compiler/rustc_borrowck/src/type_check/canonical.rs
index 86cd8b918fc6e..b58691fbeae3a 100644
--- a/compiler/rustc_borrowck/src/type_check/canonical.rs
+++ b/compiler/rustc_borrowck/src/type_check/canonical.rs
@@ -7,6 +7,7 @@ use rustc_middle::mir::ConstraintCategory;
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable, Upcast};
 use rustc_span::def_id::DefId;
 use rustc_span::Span;
+use rustc_trait_selection::traits::query::type_op::custom::CustomTypeOp;
 use rustc_trait_selection::traits::query::type_op::{self, TypeOpOutput};
 use rustc_trait_selection::traits::ObligationCause;
 
@@ -165,6 +166,52 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         result.unwrap_or(value)
     }
 
+    #[instrument(skip(self), level = "debug")]
+    pub(super) fn struct_tail(
+        &mut self,
+        ty: Ty<'tcx>,
+        location: impl NormalizeLocation,
+    ) -> Ty<'tcx> {
+        let tcx = self.tcx();
+        if self.infcx.next_trait_solver() {
+            let body = self.body;
+            let param_env = self.param_env;
+            self.fully_perform_op(
+                location.to_locations(),
+                ConstraintCategory::Boring,
+                CustomTypeOp::new(
+                    |ocx| {
+                        let structurally_normalize = |ty| {
+                            ocx.structurally_normalize(
+                                &ObligationCause::misc(
+                                    location.to_locations().span(body),
+                                    body.source.def_id().expect_local(),
+                                ),
+                                param_env,
+                                ty,
+                            )
+                            .unwrap_or_else(|_| bug!("struct tail should have been computable, since we computed it in HIR"))
+                        };
+
+                        let tail = tcx.struct_tail_raw(
+                            ty,
+                            structurally_normalize,
+                            || {},
+                        );
+
+                        Ok(tail)
+                    },
+                    "normalizing struct tail",
+                ),
+            )
+            .unwrap_or_else(|guar| Ty::new_error(tcx, guar))
+        } else {
+            let mut normalize = |ty| self.normalize(ty, location);
+            let tail = tcx.struct_tail_raw(ty, &mut normalize, || {});
+            normalize(tail)
+        }
+    }
+
     #[instrument(skip(self), level = "debug")]
     pub(super) fn ascribe_user_type(
         &mut self,
diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs
index b13773ffe1460..6bab0f33c198c 100644
--- a/compiler/rustc_borrowck/src/type_check/mod.rs
+++ b/compiler/rustc_borrowck/src/type_check/mod.rs
@@ -2329,17 +2329,8 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                         let cast_ty_to = CastTy::from_ty(*ty);
                         match (cast_ty_from, cast_ty_to) {
                             (Some(CastTy::Ptr(src)), Some(CastTy::Ptr(dst))) => {
-                                let mut normalize = |t| self.normalize(t, location);
-
-                                // N.B. `struct_tail_with_normalize` only "structurally resolves"
-                                // the type. It is not fully normalized, so we have to normalize it
-                                // afterwards.
-                                let src_tail =
-                                    tcx.struct_tail_with_normalize(src.ty, &mut normalize, || ());
-                                let src_tail = normalize(src_tail);
-                                let dst_tail =
-                                    tcx.struct_tail_with_normalize(dst.ty, &mut normalize, || ());
-                                let dst_tail = normalize(dst_tail);
+                                let src_tail = self.struct_tail(src.ty, location);
+                                let dst_tail = self.struct_tail(dst.ty, location);
 
                                 // This checks (lifetime part of) vtable validity for pointer casts,
                                 // which is irrelevant when there are aren't principal traits on both sides (aka only auto traits).
diff --git a/compiler/rustc_codegen_llvm/src/asm.rs b/compiler/rustc_codegen_llvm/src/asm.rs
index aea8395441a86..f931698c38f91 100644
--- a/compiler/rustc_codegen_llvm/src/asm.rs
+++ b/compiler/rustc_codegen_llvm/src/asm.rs
@@ -1,3 +1,5 @@
+use std::assert_matches::assert_matches;
+
 use libc::{c_char, c_uint};
 use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece};
 use rustc_codegen_ssa::mir::operand::OperandValue;
@@ -89,7 +91,7 @@ impl<'ll, 'tcx> AsmBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> {
                         // if the target feature needed by the register class is
                         // disabled. This is necessary otherwise LLVM will try
                         // to actually allocate a register for the dummy output.
-                        assert!(matches!(reg, InlineAsmRegOrRegClass::Reg(_)));
+                        assert_matches!(reg, InlineAsmRegOrRegClass::Reg(_));
                         clobbers.push(format!("~{}", reg_to_llvm(reg, None)));
                         continue;
                     } else {
diff --git a/compiler/rustc_codegen_llvm/src/back/archive.rs b/compiler/rustc_codegen_llvm/src/back/archive.rs
index a2ab19ac800b7..60e6346254877 100644
--- a/compiler/rustc_codegen_llvm/src/back/archive.rs
+++ b/compiler/rustc_codegen_llvm/src/back/archive.rs
@@ -106,9 +106,11 @@ pub struct LlvmArchiveBuilderBuilder;
 
 impl ArchiveBuilderBuilder for LlvmArchiveBuilderBuilder {
     fn new_archive_builder<'a>(&self, sess: &'a Session) -> Box<dyn ArchiveBuilder + 'a> {
-        // FIXME use ArArchiveBuilder on most targets again once reading thin archives is
-        // implemented
-        if true {
+        // Keeping LlvmArchiveBuilder around in case of a regression caused by using
+        // ArArchiveBuilder.
+        // FIXME(#128955) remove a couple of months after #128936 gets merged in case
+        // no regression is found.
+        if false {
             Box::new(LlvmArchiveBuilder { sess, additions: Vec::new() })
         } else {
             Box::new(ArArchiveBuilder::new(sess, &LLVM_OBJECT_READER))
diff --git a/compiler/rustc_codegen_llvm/src/intrinsic.rs b/compiler/rustc_codegen_llvm/src/intrinsic.rs
index 57d5f6fdf503f..f5558723d11bf 100644
--- a/compiler/rustc_codegen_llvm/src/intrinsic.rs
+++ b/compiler/rustc_codegen_llvm/src/intrinsic.rs
@@ -1,3 +1,4 @@
+use std::assert_matches::assert_matches;
 use std::cmp::Ordering;
 
 use rustc_codegen_ssa::base::{compare_simd_types, wants_msvc_seh, wants_wasm_eh};
@@ -1142,7 +1143,7 @@ fn generic_simd_intrinsic<'ll, 'tcx>(
     if cfg!(debug_assertions) {
         for (ty, arg) in arg_tys.iter().zip(args) {
             if ty.is_simd() {
-                assert!(matches!(arg.val, OperandValue::Immediate(_)));
+                assert_matches!(arg.val, OperandValue::Immediate(_));
             }
         }
     }
diff --git a/compiler/rustc_codegen_llvm/src/lib.rs b/compiler/rustc_codegen_llvm/src/lib.rs
index 518a86e0cb06d..43164390a1c6c 100644
--- a/compiler/rustc_codegen_llvm/src/lib.rs
+++ b/compiler/rustc_codegen_llvm/src/lib.rs
@@ -8,6 +8,7 @@
 #![allow(internal_features)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
+#![feature(assert_matches)]
 #![feature(exact_size_is_empty)]
 #![feature(extern_types)]
 #![feature(hash_raw_entry)]
diff --git a/compiler/rustc_codegen_ssa/src/back/archive.rs b/compiler/rustc_codegen_ssa/src/back/archive.rs
index ce55d99f506d5..8eb44d1201640 100644
--- a/compiler/rustc_codegen_ssa/src/back/archive.rs
+++ b/compiler/rustc_codegen_ssa/src/back/archive.rs
@@ -307,10 +307,15 @@ impl<'a> ArchiveBuilder for ArArchiveBuilder<'a> {
             let file_name = String::from_utf8(entry.name().to_vec())
                 .map_err(|err| io::Error::new(io::ErrorKind::InvalidData, err))?;
             if !skip(&file_name) {
-                self.entries.push((
-                    file_name.into_bytes(),
-                    ArchiveEntry::FromArchive { archive_index, file_range: entry.file_range() },
-                ));
+                if entry.is_thin() {
+                    let member_path = archive_path.parent().unwrap().join(Path::new(&file_name));
+                    self.entries.push((file_name.into_bytes(), ArchiveEntry::File(member_path)));
+                } else {
+                    self.entries.push((
+                        file_name.into_bytes(),
+                        ArchiveEntry::FromArchive { archive_index, file_range: entry.file_range() },
+                    ));
+                }
             }
         }
 
diff --git a/compiler/rustc_codegen_ssa/src/back/write.rs b/compiler/rustc_codegen_ssa/src/back/write.rs
index bea12747a5199..70b45a852ca0e 100644
--- a/compiler/rustc_codegen_ssa/src/back/write.rs
+++ b/compiler/rustc_codegen_ssa/src/back/write.rs
@@ -1,4 +1,5 @@
 use std::any::Any;
+use std::assert_matches::assert_matches;
 use std::marker::PhantomData;
 use std::path::{Path, PathBuf};
 use std::sync::mpsc::{channel, Receiver, Sender};
@@ -1963,7 +1964,7 @@ impl SharedEmitterMain {
                     sess.dcx().abort_if_errors();
                 }
                 Ok(SharedEmitterMessage::InlineAsmError(cookie, msg, level, source)) => {
-                    assert!(matches!(level, Level::Error | Level::Warning | Level::Note));
+                    assert_matches!(level, Level::Error | Level::Warning | Level::Note);
                     let msg = msg.strip_prefix("error: ").unwrap_or(&msg).to_string();
                     let mut err = Diag::<()>::new(sess.dcx(), level, msg);
 
diff --git a/compiler/rustc_codegen_ssa/src/lib.rs b/compiler/rustc_codegen_ssa/src/lib.rs
index 1b029660433bd..cb6d9d6f66e78 100644
--- a/compiler/rustc_codegen_ssa/src/lib.rs
+++ b/compiler/rustc_codegen_ssa/src/lib.rs
@@ -4,6 +4,7 @@
 #![allow(rustc::untranslatable_diagnostic)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(if_let_guard)]
 #![feature(let_chains)]
diff --git a/compiler/rustc_codegen_ssa/src/mir/operand.rs b/compiler/rustc_codegen_ssa/src/mir/operand.rs
index 2bc2d0f70bfaf..c57ad1384ac98 100644
--- a/compiler/rustc_codegen_ssa/src/mir/operand.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/operand.rs
@@ -1,3 +1,4 @@
+use std::assert_matches::assert_matches;
 use std::fmt;
 
 use arrayvec::ArrayVec;
@@ -389,7 +390,7 @@ impl<'a, 'tcx, V: CodegenObject> OperandRef<'tcx, V> {
             }
             // Newtype vector of array, e.g. #[repr(simd)] struct S([i32; 4]);
             (OperandValue::Immediate(llval), Abi::Aggregate { sized: true }) => {
-                assert!(matches!(self.layout.abi, Abi::Vector { .. }));
+                assert_matches!(self.layout.abi, Abi::Vector { .. });
 
                 let llfield_ty = bx.cx().backend_type(field);
 
diff --git a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs
index d91a118bc71a3..3c2c29ac7f7d2 100644
--- a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs
@@ -1,3 +1,5 @@
+use std::assert_matches::assert_matches;
+
 use arrayvec::ArrayVec;
 use rustc_middle::ty::adjustment::PointerCoercion;
 use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf, TyAndLayout};
@@ -220,7 +222,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         match operand.val {
             OperandValue::Ref(source_place_val) => {
                 assert_eq!(source_place_val.llextra, None);
-                assert!(matches!(operand_kind, OperandValueKind::Ref));
+                assert_matches!(operand_kind, OperandValueKind::Ref);
                 Some(bx.load_operand(source_place_val.with_type(cast)).val)
             }
             OperandValue::ZeroSized => {
diff --git a/compiler/rustc_codegen_ssa/src/traits/builder.rs b/compiler/rustc_codegen_ssa/src/traits/builder.rs
index 2b802240e03b9..6cf84a012f061 100644
--- a/compiler/rustc_codegen_ssa/src/traits/builder.rs
+++ b/compiler/rustc_codegen_ssa/src/traits/builder.rs
@@ -1,3 +1,5 @@
+use std::assert_matches::assert_matches;
+
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrs;
 use rustc_middle::ty::layout::{HasParamEnv, TyAndLayout};
 use rustc_middle::ty::{Instance, Ty};
@@ -254,10 +256,10 @@ pub trait BuilderMethods<'a, 'tcx>:
         } else {
             (in_ty, dest_ty)
         };
-        assert!(matches!(
+        assert_matches!(
             self.cx().type_kind(float_ty),
             TypeKind::Half | TypeKind::Float | TypeKind::Double | TypeKind::FP128
-        ));
+        );
         assert_eq!(self.cx().type_kind(int_ty), TypeKind::Integer);
 
         if let Some(false) = self.cx().sess().opts.unstable_opts.saturating_float_casts {
diff --git a/compiler/rustc_const_eval/messages.ftl b/compiler/rustc_const_eval/messages.ftl
index c64c73b232340..1442f1832b9b5 100644
--- a/compiler/rustc_const_eval/messages.ftl
+++ b/compiler/rustc_const_eval/messages.ftl
@@ -41,6 +41,8 @@ const_eval_const_context = {$kind ->
     *[other] {""}
 }
 
+const_eval_const_stable = const-stable functions can only call other const-stable functions
+
 const_eval_copy_nonoverlapping_overlapping =
     `copy_nonoverlapping` called on overlapping ranges
 
@@ -201,6 +203,9 @@ const_eval_invalid_vtable_pointer =
 const_eval_invalid_vtable_trait =
     using vtable for trait `{$vtable_trait}` but trait `{$expected_trait}` was expected
 
+const_eval_lazy_lock =
+    consider wrapping this expression in `std::sync::LazyLock::new(|| ...)`
+
 const_eval_live_drop =
     destructor of `{$dropped_ty}` cannot be evaluated at compile-time
     .label = the destructor for this type cannot be evaluated in {const_eval_const_context}s
diff --git a/compiler/rustc_const_eval/src/check_consts/check.rs b/compiler/rustc_const_eval/src/check_consts/check.rs
index 3ded81b90ffc1..844f3f3d6113c 100644
--- a/compiler/rustc_const_eval/src/check_consts/check.rs
+++ b/compiler/rustc_const_eval/src/check_consts/check.rs
@@ -1,5 +1,6 @@
 //! The `Visitor` responsible for actually checking a `mir::Body` for invalid operations.
 
+use std::assert_matches::assert_matches;
 use std::mem;
 use std::ops::Deref;
 
@@ -590,7 +591,7 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
                 if is_int_bool_or_char(lhs_ty) && is_int_bool_or_char(rhs_ty) {
                     // Int, bool, and char operations are fine.
                 } else if lhs_ty.is_fn_ptr() || lhs_ty.is_unsafe_ptr() {
-                    assert!(matches!(
+                    assert_matches!(
                         op,
                         BinOp::Eq
                             | BinOp::Ne
@@ -599,7 +600,7 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
                             | BinOp::Ge
                             | BinOp::Gt
                             | BinOp::Offset
-                    ));
+                    );
 
                     self.check_op(ops::RawPtrComparison);
                 } else if lhs_ty.is_floating_point() || rhs_ty.is_floating_point() {
diff --git a/compiler/rustc_const_eval/src/check_consts/ops.rs b/compiler/rustc_const_eval/src/check_consts/ops.rs
index f47a2ec8f7598..c6361710ac9ca 100644
--- a/compiler/rustc_const_eval/src/check_consts/ops.rs
+++ b/compiler/rustc_const_eval/src/check_consts/ops.rs
@@ -23,7 +23,7 @@ use rustc_trait_selection::traits::SelectionContext;
 use tracing::debug;
 
 use super::ConstCx;
-use crate::errors;
+use crate::{errors, fluent_generated};
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub enum Status {
@@ -310,7 +310,7 @@ impl<'tcx> NonConstOp<'tcx> for FnCallNonConst<'tcx> {
         }
 
         if let ConstContext::Static(_) = ccx.const_kind() {
-            err.note("consider wrapping this expression in `std::sync::LazyLock::new(|| ...)`");
+            err.note(fluent_generated::const_eval_lazy_lock);
         }
 
         err
@@ -334,7 +334,7 @@ impl<'tcx> NonConstOp<'tcx> for FnCallUnstable {
         // FIXME: make this translatable
         #[allow(rustc::untranslatable_diagnostic)]
         if ccx.is_const_stable_const_fn() {
-            err.help("const-stable functions can only call other const-stable functions");
+            err.help(fluent_generated::const_eval_const_stable);
         } else if ccx.tcx.sess.is_nightly_build() {
             if let Some(feature) = feature {
                 err.help(format!("add `#![feature({feature})]` to the crate attributes to enable"));
@@ -605,8 +605,6 @@ impl<'tcx> NonConstOp<'tcx> for StaticAccess {
             span,
             format!("referencing statics in {}s is unstable", ccx.const_kind(),),
         );
-        // FIXME: make this translatable
-        #[allow(rustc::untranslatable_diagnostic)]
         err
             .note("`static` and `const` variables can refer to other `const` variables. A `const` variable, however, cannot refer to a `static` variable.")
             .help("to fix this, the value can be extracted to a `const` and then used.");
diff --git a/compiler/rustc_const_eval/src/const_eval/eval_queries.rs b/compiler/rustc_const_eval/src/const_eval/eval_queries.rs
index ff27e4000163a..96b3ec6f18728 100644
--- a/compiler/rustc_const_eval/src/const_eval/eval_queries.rs
+++ b/compiler/rustc_const_eval/src/const_eval/eval_queries.rs
@@ -226,7 +226,7 @@ pub(super) fn op_to_const<'tcx>(
                 let pointee_ty = imm.layout.ty.builtin_deref(false).unwrap(); // `false` = no raw ptrs
                 debug_assert!(
                     matches!(
-                        ecx.tcx.struct_tail_without_normalization(pointee_ty).kind(),
+                        ecx.tcx.struct_tail_for_codegen(pointee_ty, ecx.param_env).kind(),
                         ty::Str | ty::Slice(..),
                     ),
                     "`ConstValue::Slice` is for slice-tailed types only, but got {}",
diff --git a/compiler/rustc_const_eval/src/const_eval/valtrees.rs b/compiler/rustc_const_eval/src/const_eval/valtrees.rs
index 8227c04594883..460c9797f3663 100644
--- a/compiler/rustc_const_eval/src/const_eval/valtrees.rs
+++ b/compiler/rustc_const_eval/src/const_eval/valtrees.rs
@@ -195,7 +195,7 @@ fn reconstruct_place_meta<'tcx>(
 
     let mut last_valtree = valtree;
     // Traverse the type, and update `last_valtree` as we go.
-    let tail = tcx.struct_tail_with_normalize(
+    let tail = tcx.struct_tail_raw(
         layout.ty,
         |ty| ty,
         || {
diff --git a/compiler/rustc_const_eval/src/interpret/call.rs b/compiler/rustc_const_eval/src/interpret/call.rs
index fdbdfc7e1b8b3..917a2fa7c6dd4 100644
--- a/compiler/rustc_const_eval/src/interpret/call.rs
+++ b/compiler/rustc_const_eval/src/interpret/call.rs
@@ -1,5 +1,6 @@
 //! Manages calling a concrete function (with known MIR body) with argument passing,
 //! and returning the return value to the caller.
+use std::assert_matches::assert_matches;
 use std::borrow::Cow;
 
 use either::{Left, Right};
@@ -557,7 +558,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                     unwind,
                 )? {
                     assert!(!self.tcx.intrinsic(fallback.def_id()).unwrap().must_be_overridden);
-                    assert!(matches!(fallback.def, ty::InstanceKind::Item(_)));
+                    assert_matches!(fallback.def, ty::InstanceKind::Item(_));
                     return self.init_fn_call(
                         FnVal::Instance(fallback),
                         (caller_abi, caller_fn_abi),
diff --git a/compiler/rustc_const_eval/src/interpret/intrinsics.rs b/compiler/rustc_const_eval/src/interpret/intrinsics.rs
index 9210ec4e16fd0..3be1b745d0057 100644
--- a/compiler/rustc_const_eval/src/interpret/intrinsics.rs
+++ b/compiler/rustc_const_eval/src/interpret/intrinsics.rs
@@ -2,6 +2,8 @@
 //! looking at their MIR. Intrinsics/functions supported here are shared by CTFE
 //! and miri.
 
+use std::assert_matches::assert_matches;
+
 use rustc_hir::def_id::DefId;
 use rustc_middle::mir::{self, BinOp, ConstValue, NonDivergingIntrinsic};
 use rustc_middle::ty::layout::{LayoutOf as _, TyAndLayout, ValidityRequirement};
@@ -510,7 +512,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         dest: &MPlaceTy<'tcx, M::Provenance>,
     ) -> InterpResult<'tcx> {
         assert_eq!(a.layout.ty, b.layout.ty);
-        assert!(matches!(a.layout.ty.kind(), ty::Int(..) | ty::Uint(..)));
+        assert_matches!(a.layout.ty.kind(), ty::Int(..) | ty::Uint(..));
 
         // Performs an exact division, resulting in undefined behavior where
         // `x % y != 0` or `y == 0` or `x == T::MIN && y == -1`.
@@ -536,8 +538,8 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         r: &ImmTy<'tcx, M::Provenance>,
     ) -> InterpResult<'tcx, Scalar<M::Provenance>> {
         assert_eq!(l.layout.ty, r.layout.ty);
-        assert!(matches!(l.layout.ty.kind(), ty::Int(..) | ty::Uint(..)));
-        assert!(matches!(mir_op, BinOp::Add | BinOp::Sub));
+        assert_matches!(l.layout.ty.kind(), ty::Int(..) | ty::Uint(..));
+        assert_matches!(mir_op, BinOp::Add | BinOp::Sub);
 
         let (val, overflowed) =
             self.binary_op(mir_op.wrapping_to_overflowing().unwrap(), l, r)?.to_scalar_pair();
diff --git a/compiler/rustc_const_eval/src/interpret/operand.rs b/compiler/rustc_const_eval/src/interpret/operand.rs
index 4ced009ab39b6..ad87d6953d3f2 100644
--- a/compiler/rustc_const_eval/src/interpret/operand.rs
+++ b/compiler/rustc_const_eval/src/interpret/operand.rs
@@ -342,7 +342,7 @@ impl<'tcx, Prov: Provenance> ImmTy<'tcx, Prov> {
             }
             // extract fields from types with `ScalarPair` ABI
             (Immediate::ScalarPair(a_val, b_val), Abi::ScalarPair(a, b)) => {
-                assert!(matches!(layout.abi, Abi::Scalar(..)));
+                assert_matches!(layout.abi, Abi::Scalar(..));
                 Immediate::from(if offset.bytes() == 0 {
                     debug_assert_eq!(layout.size, a.size(cx));
                     a_val
diff --git a/compiler/rustc_data_structures/src/graph/scc/mod.rs b/compiler/rustc_data_structures/src/graph/scc/mod.rs
index 96fc8ae3887f5..2a457ffb70b08 100644
--- a/compiler/rustc_data_structures/src/graph/scc/mod.rs
+++ b/compiler/rustc_data_structures/src/graph/scc/mod.rs
@@ -8,6 +8,7 @@
 //! Typical examples would include: minimum element in SCC, maximum element
 //! reachable from it, etc.
 
+use std::assert_matches::debug_assert_matches;
 use std::fmt::Debug;
 use std::ops::Range;
 
@@ -569,7 +570,7 @@ where
                     // This None marks that we still have the initialize this node's frame.
                     debug!(?depth, ?node);
 
-                    debug_assert!(matches!(self.node_states[node], NodeState::NotVisited));
+                    debug_assert_matches!(self.node_states[node], NodeState::NotVisited);
 
                     // Push `node` onto the stack.
                     self.node_states[node] = NodeState::BeingVisited {
diff --git a/compiler/rustc_data_structures/src/lib.rs b/compiler/rustc_data_structures/src/lib.rs
index 403136e78f4eb..a35f5b1f17db4 100644
--- a/compiler/rustc_data_structures/src/lib.rs
+++ b/compiler/rustc_data_structures/src/lib.rs
@@ -18,6 +18,7 @@
 #![feature(array_windows)]
 #![feature(ascii_char)]
 #![feature(ascii_char_variants)]
+#![feature(assert_matches)]
 #![feature(auto_traits)]
 #![feature(cfg_match)]
 #![feature(core_intrinsics)]
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index aefbf05a1fcc6..3bc03a1e51655 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -10,6 +10,7 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(array_windows)]
+#![feature(assert_matches)]
 #![feature(associated_type_defaults)]
 #![feature(box_into_inner)]
 #![feature(box_patterns)]
@@ -28,6 +29,7 @@
 
 extern crate self as rustc_errors;
 
+use std::assert_matches::assert_matches;
 use std::backtrace::{Backtrace, BacktraceStatus};
 use std::borrow::Cow;
 use std::cell::Cell;
@@ -1490,7 +1492,7 @@ impl DiagCtxtInner {
             // Future breakages aren't emitted if they're `Level::Allow` or
             // `Level::Expect`, but they still need to be constructed and
             // stashed below, so they'll trigger the must_produce_diag check.
-            assert!(matches!(diagnostic.level, Error | Warning | Allow | Expect(_)));
+            assert_matches!(diagnostic.level, Error | Warning | Allow | Expect(_));
             self.future_breakage_diagnostics.push(diagnostic.clone());
         }
 
diff --git a/compiler/rustc_expand/messages.ftl b/compiler/rustc_expand/messages.ftl
index 18d95a398fd4f..766d96e268f04 100644
--- a/compiler/rustc_expand/messages.ftl
+++ b/compiler/rustc_expand/messages.ftl
@@ -129,6 +129,9 @@ expand_module_multiple_candidates =
 expand_must_repeat_once =
     this must repeat at least once
 
+expand_non_inline_modules_in_proc_macro_input_are_unstable =
+    non-inline modules in proc macro input are unstable
+
 expand_not_a_meta_item =
     not a meta item
 
diff --git a/compiler/rustc_expand/src/base.rs b/compiler/rustc_expand/src/base.rs
index 7712915d490db..8f9104135cddd 100644
--- a/compiler/rustc_expand/src/base.rs
+++ b/compiler/rustc_expand/src/base.rs
@@ -1398,8 +1398,6 @@ fn pretty_printing_compatibility_hack(item: &Item, sess: &Session) {
         };
 
         if crate_matches {
-            // FIXME: make this translatable
-            #[allow(rustc::untranslatable_diagnostic)]
             sess.dcx().emit_fatal(errors::ProcMacroBackCompat {
                 crate_name: "rental".to_string(),
                 fixed_version: "0.5.6".to_string(),
diff --git a/compiler/rustc_expand/src/expand.rs b/compiler/rustc_expand/src/expand.rs
index d8cb367e3face..37679e17b90a8 100644
--- a/compiler/rustc_expand/src/expand.rs
+++ b/compiler/rustc_expand/src/expand.rs
@@ -39,6 +39,7 @@ use crate::errors::{
     RecursionLimitReached, RemoveExprNotSupported, RemoveNodeNotSupported, UnsupportedKeyValue,
     WrongFragmentKind,
 };
+use crate::fluent_generated;
 use crate::mbe::diagnostics::annotate_err_with_kind;
 use crate::module::{mod_dir_path, parse_external_mod, DirOwnership, ParsedExternalMod};
 use crate::placeholders::{placeholder, PlaceholderExpander};
@@ -882,7 +883,6 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
         }
 
         impl<'ast, 'a> Visitor<'ast> for GateProcMacroInput<'a> {
-            #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
             fn visit_item(&mut self, item: &'ast ast::Item) {
                 match &item.kind {
                     ItemKind::Mod(_, mod_kind)
@@ -892,7 +892,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                             self.sess,
                             sym::proc_macro_hygiene,
                             item.span,
-                            "non-inline modules in proc macro input are unstable",
+                            fluent_generated::expand_non_inline_modules_in_proc_macro_input_are_unstable,
                         )
                         .emit();
                     }
@@ -1876,7 +1876,6 @@ impl<'a, 'b> InvocationCollector<'a, 'b> {
 
     // Detect use of feature-gated or invalid attributes on macro invocations
     // since they will not be detected after macro expansion.
-    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn check_attributes(&self, attrs: &[ast::Attribute], call: &ast::MacCall) {
         let features = self.cx.ecfg.features;
         let mut attrs = attrs.iter().peekable();
diff --git a/compiler/rustc_hir_analysis/src/check/intrinsicck.rs b/compiler/rustc_hir_analysis/src/check/intrinsicck.rs
index 847a1e6470679..79ecdee448603 100644
--- a/compiler/rustc_hir_analysis/src/check/intrinsicck.rs
+++ b/compiler/rustc_hir_analysis/src/check/intrinsicck.rs
@@ -1,3 +1,5 @@
+use std::assert_matches::debug_assert_matches;
+
 use rustc_ast::InlineAsmTemplatePiece;
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_hir::{self as hir, LangItem};
@@ -457,17 +459,17 @@ impl<'a, 'tcx> InlineAsmCtxt<'a, 'tcx> {
                 }
                 // Typeck has checked that Const operands are integers.
                 hir::InlineAsmOperand::Const { anon_const } => {
-                    debug_assert!(matches!(
+                    debug_assert_matches!(
                         self.tcx.type_of(anon_const.def_id).instantiate_identity().kind(),
                         ty::Error(_) | ty::Int(_) | ty::Uint(_)
-                    ));
+                    );
                 }
                 // Typeck has checked that SymFn refers to a function.
                 hir::InlineAsmOperand::SymFn { anon_const } => {
-                    debug_assert!(matches!(
+                    debug_assert_matches!(
                         self.tcx.type_of(anon_const.def_id).instantiate_identity().kind(),
                         ty::Error(_) | ty::FnDef(..)
-                    ));
+                    );
                 }
                 // AST lowering guarantees that SymStatic points to a static.
                 hir::InlineAsmOperand::SymStatic { .. } => {}
diff --git a/compiler/rustc_hir_analysis/src/coherence/builtin.rs b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
index bdb5f5b720529..fecd78bc38f47 100644
--- a/compiler/rustc_hir_analysis/src/coherence/builtin.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
@@ -1,6 +1,7 @@
 //! Check properties that are required by built-in traits and set
 //! up data structures required by type-checking/codegen.
 
+use std::assert_matches::assert_matches;
 use std::collections::BTreeMap;
 
 use rustc_data_structures::fx::FxHashSet;
@@ -129,7 +130,7 @@ fn visit_implementation_of_const_param_ty(
     checker: &Checker<'_>,
     kind: LangItem,
 ) -> Result<(), ErrorGuaranteed> {
-    assert!(matches!(kind, LangItem::ConstParamTy | LangItem::UnsizedConstParamTy));
+    assert_matches!(kind, LangItem::ConstParamTy | LangItem::UnsizedConstParamTy);
 
     let tcx = checker.tcx;
     let header = checker.impl_header;
diff --git a/compiler/rustc_hir_analysis/src/collect.rs b/compiler/rustc_hir_analysis/src/collect.rs
index 8c1e5e78b75dc..91fa066ec6a1d 100644
--- a/compiler/rustc_hir_analysis/src/collect.rs
+++ b/compiler/rustc_hir_analysis/src/collect.rs
@@ -1700,6 +1700,8 @@ fn impl_trait_header(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Option<ty::ImplTrai
             trait_ref: ty::EarlyBinder::bind(trait_ref),
             safety: impl_.safety,
             polarity: polarity_of_impl(tcx, def_id, impl_, item.span),
+            do_not_recommend: tcx.features().do_not_recommend
+                && tcx.has_attrs_with_path(def_id, &[sym::diagnostic, sym::do_not_recommend]),
         }
     })
 }
diff --git a/compiler/rustc_hir_analysis/src/collect/generics_of.rs b/compiler/rustc_hir_analysis/src/collect/generics_of.rs
index 60e2c2eb30e56..28d6cab4b439a 100644
--- a/compiler/rustc_hir_analysis/src/collect/generics_of.rs
+++ b/compiler/rustc_hir_analysis/src/collect/generics_of.rs
@@ -1,3 +1,4 @@
+use std::assert_matches::assert_matches;
 use std::ops::ControlFlow;
 
 use hir::intravisit::{self, Visitor};
@@ -207,9 +208,9 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
                 ..
             }) => {
                 if in_trait {
-                    assert!(matches!(tcx.def_kind(fn_def_id), DefKind::AssocFn))
+                    assert_matches!(tcx.def_kind(fn_def_id), DefKind::AssocFn);
                 } else {
-                    assert!(matches!(tcx.def_kind(fn_def_id), DefKind::AssocFn | DefKind::Fn))
+                    assert_matches!(tcx.def_kind(fn_def_id), DefKind::AssocFn | DefKind::Fn);
                 }
                 Some(fn_def_id.to_def_id())
             }
@@ -218,9 +219,9 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
                 ..
             }) => {
                 if in_assoc_ty {
-                    assert!(matches!(tcx.def_kind(parent), DefKind::AssocTy));
+                    assert_matches!(tcx.def_kind(parent), DefKind::AssocTy);
                 } else {
-                    assert!(matches!(tcx.def_kind(parent), DefKind::TyAlias));
+                    assert_matches!(tcx.def_kind(parent), DefKind::TyAlias);
                 }
                 debug!("generics_of: parent of opaque ty {:?} is {:?}", def_id, parent);
                 // Opaque types are always nested within another item, and
diff --git a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
index a5a56cb845d79..6ac4802b19514 100644
--- a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
+++ b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
@@ -1,3 +1,5 @@
+use std::assert_matches::assert_matches;
+
 use hir::{HirId, Node};
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_hir as hir;
@@ -601,7 +603,7 @@ pub(super) fn implied_predicates_with_filter(
     let Some(trait_def_id) = trait_def_id.as_local() else {
         // if `assoc_name` is None, then the query should've been redirected to an
         // external provider
-        assert!(matches!(filter, PredicateFilter::SelfThatDefines(_)));
+        assert_matches!(filter, PredicateFilter::SelfThatDefines(_));
         return tcx.explicit_super_predicates_of(trait_def_id);
     };
 
diff --git a/compiler/rustc_hir_analysis/src/delegation.rs b/compiler/rustc_hir_analysis/src/delegation.rs
index ca62ef92b83de..20aaa43219f34 100644
--- a/compiler/rustc_hir_analysis/src/delegation.rs
+++ b/compiler/rustc_hir_analysis/src/delegation.rs
@@ -1,3 +1,5 @@
+use std::assert_matches::debug_assert_matches;
+
 use rustc_data_structures::fx::FxHashMap;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{DefId, LocalDefId};
@@ -63,7 +65,7 @@ enum FnKind {
 }
 
 fn fn_kind<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> FnKind {
-    debug_assert!(matches!(tcx.def_kind(def_id), DefKind::Fn | DefKind::AssocFn));
+    debug_assert_matches!(tcx.def_kind(def_id), DefKind::Fn | DefKind::AssocFn);
 
     let parent = tcx.parent(def_id);
     match tcx.def_kind(parent) {
diff --git a/compiler/rustc_hir_analysis/src/impl_wf_check.rs b/compiler/rustc_hir_analysis/src/impl_wf_check.rs
index a8ae620f7a49d..ab441ed4cde99 100644
--- a/compiler/rustc_hir_analysis/src/impl_wf_check.rs
+++ b/compiler/rustc_hir_analysis/src/impl_wf_check.rs
@@ -8,6 +8,8 @@
 //! specialization errors. These things can (and probably should) be
 //! fixed, but for the moment it's easier to do these checks early.
 
+use std::assert_matches::debug_assert_matches;
+
 use min_specialization::check_min_specialization;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::codes::*;
@@ -54,7 +56,7 @@ mod min_specialization;
 pub fn check_impl_wf(tcx: TyCtxt<'_>, impl_def_id: LocalDefId) -> Result<(), ErrorGuaranteed> {
     let min_specialization = tcx.features().min_specialization;
     let mut res = Ok(());
-    debug_assert!(matches!(tcx.def_kind(impl_def_id), DefKind::Impl { .. }));
+    debug_assert_matches!(tcx.def_kind(impl_def_id), DefKind::Impl { .. });
     res = res.and(enforce_impl_params_are_constrained(tcx, impl_def_id));
     if min_specialization {
         res = res.and(check_min_specialization(tcx, impl_def_id));
diff --git a/compiler/rustc_hir_analysis/src/lib.rs b/compiler/rustc_hir_analysis/src/lib.rs
index 061db14ad0a61..291d57f2a176f 100644
--- a/compiler/rustc_hir_analysis/src/lib.rs
+++ b/compiler/rustc_hir_analysis/src/lib.rs
@@ -62,6 +62,7 @@ This API is completely unstable and subject to change.
 #![allow(rustc::untranslatable_diagnostic)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
+#![feature(assert_matches)]
 #![feature(control_flow_enum)]
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]
diff --git a/compiler/rustc_hir_typeck/src/cast.rs b/compiler/rustc_hir_typeck/src/cast.rs
index de70273390466..7cd97166ed1e9 100644
--- a/compiler/rustc_hir_typeck/src/cast.rs
+++ b/compiler/rustc_hir_typeck/src/cast.rs
@@ -97,6 +97,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             return Ok(Some(PointerKind::Thin));
         }
 
+        let t = self.try_structurally_resolve_type(span, t);
+
         Ok(match *t.kind() {
             ty::Slice(_) | ty::Str => Some(PointerKind::Length),
             ty::Dynamic(tty, _, ty::Dyn) => Some(PointerKind::VTable(tty)),
diff --git a/compiler/rustc_hir_typeck/src/expectation.rs b/compiler/rustc_hir_typeck/src/expectation.rs
index 91deae4174b00..76ae41db5c51c 100644
--- a/compiler/rustc_hir_typeck/src/expectation.rs
+++ b/compiler/rustc_hir_typeck/src/expectation.rs
@@ -70,7 +70,8 @@ impl<'a, 'tcx> Expectation<'tcx> {
     /// See the test case `test/ui/coerce-expect-unsized.rs` and #20169
     /// for examples of where this comes up,.
     pub(super) fn rvalue_hint(fcx: &FnCtxt<'a, 'tcx>, ty: Ty<'tcx>) -> Expectation<'tcx> {
-        match fcx.tcx.struct_tail_without_normalization(ty).kind() {
+        // FIXME: This is not right, even in the old solver...
+        match fcx.tcx.struct_tail_raw(ty, |ty| ty, || {}).kind() {
             ty::Slice(_) | ty::Str | ty::Dynamic(..) => ExpectRvalueLikeUnsized(ty),
             _ => ExpectHasType(ty),
         }
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
index 841d25b54cc88..b169f75796b3a 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
@@ -404,7 +404,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         code: traits::ObligationCauseCode<'tcx>,
     ) {
         if !ty.references_error() {
-            let tail = self.tcx.struct_tail_with_normalize(
+            let tail = self.tcx.struct_tail_raw(
                 ty,
                 |ty| {
                     if self.next_trait_solver() {
diff --git a/compiler/rustc_infer/src/infer/outlives/verify.rs b/compiler/rustc_infer/src/infer/outlives/verify.rs
index c3d37d9986f6c..1908e1e09c3d5 100644
--- a/compiler/rustc_infer/src/infer/outlives/verify.rs
+++ b/compiler/rustc_infer/src/infer/outlives/verify.rs
@@ -1,3 +1,5 @@
+use std::assert_matches::assert_matches;
+
 use rustc_middle::ty::{self, OutlivesPredicate, Ty, TyCtxt};
 use rustc_type_ir::outlives::{compute_alias_components_recursive, Component};
 use smallvec::smallvec;
@@ -181,7 +183,7 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> {
         &self,
         generic_ty: Ty<'tcx>,
     ) -> Vec<ty::PolyTypeOutlivesPredicate<'tcx>> {
-        assert!(matches!(generic_ty.kind(), ty::Param(_) | ty::Placeholder(_)));
+        assert_matches!(generic_ty.kind(), ty::Param(_) | ty::Placeholder(_));
         self.declared_generic_bounds_from_env_for_erased_ty(generic_ty)
     }
 
diff --git a/compiler/rustc_infer/src/lib.rs b/compiler/rustc_infer/src/lib.rs
index b65ac8596675a..25ac8ba974bb6 100644
--- a/compiler/rustc_infer/src/lib.rs
+++ b/compiler/rustc_infer/src/lib.rs
@@ -18,6 +18,7 @@
 #![allow(rustc::untranslatable_diagnostic)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(control_flow_enum)]
 #![feature(extend_one)]
diff --git a/compiler/rustc_interface/src/util.rs b/compiler/rustc_interface/src/util.rs
index 6f53b1c90313b..761d288a7c2eb 100644
--- a/compiler/rustc_interface/src/util.rs
+++ b/compiler/rustc_interface/src/util.rs
@@ -386,7 +386,6 @@ fn get_codegen_sysroot(
     }
 }
 
-#[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
 pub(crate) fn check_attr_crate_type(
     sess: &Session,
     attrs: &[ast::Attribute],
diff --git a/compiler/rustc_lint/src/levels.rs b/compiler/rustc_lint/src/levels.rs
index 72920fd045fd4..44117e5d7a573 100644
--- a/compiler/rustc_lint/src/levels.rs
+++ b/compiler/rustc_lint/src/levels.rs
@@ -717,7 +717,6 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
         };
     }
 
-    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn add(&mut self, attrs: &[ast::Attribute], is_crate_node: bool, source_hir_id: Option<HirId>) {
         let sess = self.sess;
         for (attr_index, attr) in attrs.iter().enumerate() {
@@ -1039,7 +1038,6 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
             let (level, src) = self.lint_level(builtin::UNKNOWN_LINTS);
             // FIXME: make this translatable
             #[allow(rustc::diagnostic_outside_of_impl)]
-            #[allow(rustc::untranslatable_diagnostic)]
             lint_level(self.sess, lint, level, src, Some(span.into()), |lint| {
                 lint.primary_message(fluent::lint_unknown_gated_lint);
                 lint.arg("name", lint_id.lint.name_lower());
diff --git a/compiler/rustc_metadata/messages.ftl b/compiler/rustc_metadata/messages.ftl
index 24fe1ebc07e40..d80aa0cc4f414 100644
--- a/compiler/rustc_metadata/messages.ftl
+++ b/compiler/rustc_metadata/messages.ftl
@@ -134,12 +134,18 @@ metadata_lib_framework_apple =
 metadata_lib_required =
     crate `{$crate_name}` required to be available in {$kind} format, but was not found in this form
 
+metadata_link_arg_unstable =
+    link kind `link-arg` is unstable
+
 metadata_link_cfg_form =
     link cfg must be of the form `cfg(/* predicate */)`
 
 metadata_link_cfg_single_predicate =
     link cfg must have a single predicate argument
 
+metadata_link_cfg_unstable =
+    link cfg is unstable
+
 metadata_link_framework_apple =
     link kind `framework` is only supported on Apple targets
 
diff --git a/compiler/rustc_metadata/src/creader.rs b/compiler/rustc_metadata/src/creader.rs
index 2fca443ffa035..14a1a7f67e56e 100644
--- a/compiler/rustc_metadata/src/creader.rs
+++ b/compiler/rustc_metadata/src/creader.rs
@@ -949,7 +949,6 @@ impl<'a, 'tcx> CrateLoader<'a, 'tcx> {
         }
     }
 
-    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn report_unused_deps(&mut self, krate: &ast::Crate) {
         // Make a point span rather than covering the whole file
         let span = krate.spans.inner_span.shrink_to_lo();
diff --git a/compiler/rustc_metadata/src/native_libs.rs b/compiler/rustc_metadata/src/native_libs.rs
index b19493d12ff33..34497f5ac53f8 100644
--- a/compiler/rustc_metadata/src/native_libs.rs
+++ b/compiler/rustc_metadata/src/native_libs.rs
@@ -17,7 +17,7 @@ use rustc_span::def_id::{DefId, LOCAL_CRATE};
 use rustc_span::symbol::{sym, Symbol};
 use rustc_target::spec::abi::Abi;
 
-use crate::errors;
+use crate::{errors, fluent_generated};
 
 pub fn find_native_static_library(name: &str, verbatim: bool, sess: &Session) -> PathBuf {
     let formats = if verbatim {
@@ -87,7 +87,6 @@ struct Collector<'tcx> {
 }
 
 impl<'tcx> Collector<'tcx> {
-    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn process_module(&mut self, module: &ForeignModule) {
         let ForeignModule { def_id, abi, ref foreign_items } = *module;
         let def_id = def_id.expect_local();
@@ -161,7 +160,7 @@ impl<'tcx> Collector<'tcx> {
                                         sess,
                                         sym::link_arg_attribute,
                                         span,
-                                        "link kind `link-arg` is unstable",
+                                        fluent_generated::metadata_link_arg_unstable,
                                     )
                                     .emit();
                                 }
@@ -201,8 +200,13 @@ impl<'tcx> Collector<'tcx> {
                             continue;
                         };
                         if !features.link_cfg {
-                            feature_err(sess, sym::link_cfg, item.span(), "link cfg is unstable")
-                                .emit();
+                            feature_err(
+                                sess,
+                                sym::link_cfg,
+                                item.span(),
+                                fluent_generated::metadata_link_cfg_unstable,
+                            )
+                            .emit();
                         }
                         cfg = Some(link_cfg.clone());
                     }
@@ -266,6 +270,8 @@ impl<'tcx> Collector<'tcx> {
 
                     macro report_unstable_modifier($feature: ident) {
                         if !features.$feature {
+                            // FIXME: make this translatable
+                            #[expect(rustc::untranslatable_diagnostic)]
                             feature_err(
                                 sess,
                                 sym::$feature,
diff --git a/compiler/rustc_middle/src/ty/consts/kind.rs b/compiler/rustc_middle/src/ty/consts/kind.rs
index 7f096dd36f8f2..c7c2e8afa1e71 100644
--- a/compiler/rustc_middle/src/ty/consts/kind.rs
+++ b/compiler/rustc_middle/src/ty/consts/kind.rs
@@ -1,3 +1,5 @@
+use std::assert_matches::assert_matches;
+
 use rustc_macros::{extension, HashStable, TyDecodable, TyEncodable, TypeFoldable, TypeVisitable};
 
 use super::Const;
@@ -80,7 +82,7 @@ impl<'tcx> Expr<'tcx> {
     }
 
     pub fn binop_args(self) -> (Ty<'tcx>, Ty<'tcx>, Const<'tcx>, Const<'tcx>) {
-        assert!(matches!(self.kind, ExprKind::Binop(_)));
+        assert_matches!(self.kind, ExprKind::Binop(_));
 
         match self.args().as_slice() {
             [lhs_ty, rhs_ty, lhs_ct, rhs_ct] => (
@@ -101,7 +103,7 @@ impl<'tcx> Expr<'tcx> {
     }
 
     pub fn unop_args(self) -> (Ty<'tcx>, Const<'tcx>) {
-        assert!(matches!(self.kind, ExprKind::UnOp(_)));
+        assert_matches!(self.kind, ExprKind::UnOp(_));
 
         match self.args().as_slice() {
             [ty, ct] => (ty.expect_ty(), ct.expect_const()),
@@ -125,7 +127,7 @@ impl<'tcx> Expr<'tcx> {
     }
 
     pub fn call_args(self) -> (Ty<'tcx>, Const<'tcx>, impl Iterator<Item = Const<'tcx>>) {
-        assert!(matches!(self.kind, ExprKind::FunctionCall));
+        assert_matches!(self.kind, ExprKind::FunctionCall);
 
         match self.args().as_slice() {
             [func_ty, func, rest @ ..] => (
@@ -152,7 +154,7 @@ impl<'tcx> Expr<'tcx> {
     }
 
     pub fn cast_args(self) -> (Ty<'tcx>, Const<'tcx>, Ty<'tcx>) {
-        assert!(matches!(self.kind, ExprKind::Cast(_)));
+        assert_matches!(self.kind, ExprKind::Cast(_));
 
         match self.args().as_slice() {
             [value_ty, value, to_ty] => {
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index 8f8fd09c9e4d9..dd367d38e4692 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -3176,6 +3176,12 @@ impl<'tcx> TyCtxt<'tcx> {
     pub fn impl_polarity(self, def_id: impl IntoQueryParam<DefId>) -> ty::ImplPolarity {
         self.impl_trait_header(def_id).map_or(ty::ImplPolarity::Positive, |h| h.polarity)
     }
+
+    /// Whether this is a trait implementation that has `#[diagnostic::do_not_recommend]`
+    pub fn do_not_recommend_impl(self, def_id: DefId) -> bool {
+        matches!(self.def_kind(def_id), DefKind::Impl { of_trait: true })
+            && self.impl_trait_header(def_id).is_some_and(|header| header.do_not_recommend)
+    }
 }
 
 /// Parameter attributes that can only be determined by examining the body of a function instead
diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs
index 9204405d58f11..684574825e345 100644
--- a/compiler/rustc_middle/src/ty/layout.rs
+++ b/compiler/rustc_middle/src/ty/layout.rs
@@ -362,7 +362,7 @@ impl<'tcx> SizeSkeleton<'tcx> {
             ty::Ref(_, pointee, _) | ty::RawPtr(pointee, _) => {
                 let non_zero = !ty.is_unsafe_ptr();
 
-                let tail = tcx.struct_tail_with_normalize(
+                let tail = tcx.struct_tail_raw(
                     pointee,
                     |ty| match tcx.try_normalize_erasing_regions(param_env, ty) {
                         Ok(ty) => ty,
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index 9736428e6f7c7..69b194045ad08 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -262,6 +262,7 @@ pub struct ImplTraitHeader<'tcx> {
     pub trait_ref: ty::EarlyBinder<'tcx, ty::TraitRef<'tcx>>,
     pub polarity: ImplPolarity,
     pub safety: hir::Safety,
+    pub do_not_recommend: bool,
 }
 
 #[derive(Copy, Clone, PartialEq, Eq, Debug, TypeFoldable, TypeVisitable)]
diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs
index 8c97de1c59b26..8781a670acb30 100644
--- a/compiler/rustc_middle/src/ty/sty.rs
+++ b/compiler/rustc_middle/src/ty/sty.rs
@@ -1590,7 +1590,7 @@ impl<'tcx> Ty<'tcx> {
         tcx: TyCtxt<'tcx>,
         normalize: impl FnMut(Ty<'tcx>) -> Ty<'tcx>,
     ) -> Result<Ty<'tcx>, Ty<'tcx>> {
-        let tail = tcx.struct_tail_with_normalize(self, normalize, || {});
+        let tail = tcx.struct_tail_raw(self, normalize, || {});
         match tail.kind() {
             // Sized types
             ty::Infer(ty::IntVar(_) | ty::FloatVar(_))
@@ -1614,10 +1614,10 @@ impl<'tcx> Ty<'tcx> {
             | ty::Foreign(..)
             // `dyn*` has metadata = ().
             | ty::Dynamic(_, _, ty::DynStar)
-            // If returned by `struct_tail_with_normalize` this is a unit struct
+            // If returned by `struct_tail_raw` this is a unit struct
             // without any fields, or not a struct, and therefore is Sized.
             | ty::Adt(..)
-            // If returned by `struct_tail_with_normalize` this is the empty tuple,
+            // If returned by `struct_tail_raw` this is the empty tuple,
             // a.k.a. unit type, which is Sized
             | ty::Tuple(..) => Ok(tcx.types.unit),
 
diff --git a/compiler/rustc_middle/src/ty/util.rs b/compiler/rustc_middle/src/ty/util.rs
index 365f434a264e2..6be3dc423deb3 100644
--- a/compiler/rustc_middle/src/ty/util.rs
+++ b/compiler/rustc_middle/src/ty/util.rs
@@ -171,14 +171,6 @@ impl<'tcx> TyCtxt<'tcx> {
         }
     }
 
-    /// Attempts to returns the deeply last field of nested structures, but
-    /// does not apply any normalization in its search. Returns the same type
-    /// if input `ty` is not a structure at all.
-    pub fn struct_tail_without_normalization(self, ty: Ty<'tcx>) -> Ty<'tcx> {
-        let tcx = self;
-        tcx.struct_tail_with_normalize(ty, |ty| ty, || {})
-    }
-
     /// Returns the deeply last field of nested structures, or the same type if
     /// not a structure at all. Corresponds to the only possible unsized field,
     /// and its type can be used to determine unsizing strategy.
@@ -188,7 +180,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// normalization attempt may cause compiler bugs.
     pub fn struct_tail_for_codegen(self, ty: Ty<'tcx>, param_env: ty::ParamEnv<'tcx>) -> Ty<'tcx> {
         let tcx = self;
-        tcx.struct_tail_with_normalize(ty, |ty| tcx.normalize_erasing_regions(param_env, ty), || {})
+        tcx.struct_tail_raw(ty, |ty| tcx.normalize_erasing_regions(param_env, ty), || {})
     }
 
     /// Returns the deeply last field of nested structures, or the same type if
@@ -196,12 +188,14 @@ impl<'tcx> TyCtxt<'tcx> {
     /// and its type can be used to determine unsizing strategy.
     ///
     /// This is parameterized over the normalization strategy (i.e. how to
-    /// handle `<T as Trait>::Assoc` and `impl Trait`); pass the identity
-    /// function to indicate no normalization should take place.
+    /// handle `<T as Trait>::Assoc` and `impl Trait`). You almost certainly do
+    /// **NOT** want to pass the identity function here, unless you know what
+    /// you're doing, or you're within normalization code itself and will handle
+    /// an unnormalized tail recursively.
     ///
     /// See also `struct_tail_for_codegen`, which is suitable for use
     /// during codegen.
-    pub fn struct_tail_with_normalize(
+    pub fn struct_tail_raw(
         self,
         mut ty: Ty<'tcx>,
         mut normalize: impl FnMut(Ty<'tcx>) -> Ty<'tcx>,
@@ -281,7 +275,7 @@ impl<'tcx> TyCtxt<'tcx> {
         param_env: ty::ParamEnv<'tcx>,
     ) -> (Ty<'tcx>, Ty<'tcx>) {
         let tcx = self;
-        tcx.struct_lockstep_tails_with_normalize(source, target, |ty| {
+        tcx.struct_lockstep_tails_raw(source, target, |ty| {
             tcx.normalize_erasing_regions(param_env, ty)
         })
     }
@@ -294,7 +288,7 @@ impl<'tcx> TyCtxt<'tcx> {
     ///
     /// See also `struct_lockstep_tails_for_codegen`, which is suitable for use
     /// during codegen.
-    pub fn struct_lockstep_tails_with_normalize(
+    pub fn struct_lockstep_tails_raw(
         self,
         source: Ty<'tcx>,
         target: Ty<'tcx>,
diff --git a/compiler/rustc_mir_dataflow/src/impls/initialized.rs b/compiler/rustc_mir_dataflow/src/impls/initialized.rs
index e9e8ddefa020b..7822fb17f7298 100644
--- a/compiler/rustc_mir_dataflow/src/impls/initialized.rs
+++ b/compiler/rustc_mir_dataflow/src/impls/initialized.rs
@@ -1,3 +1,5 @@
+use std::assert_matches::assert_matches;
+
 use rustc_index::bit_set::{BitSet, ChunkedBitSet};
 use rustc_index::Idx;
 use rustc_middle::bug;
@@ -496,7 +498,7 @@ impl<'tcx> GenKillAnalysis<'tcx> for MaybeUninitializedPlaces<'_, '_, 'tcx> {
         });
         if self.skip_unreachable_unwind.contains(location.block) {
             let mir::TerminatorKind::Drop { target, unwind, .. } = terminator.kind else { bug!() };
-            assert!(matches!(unwind, mir::UnwindAction::Cleanup(_)));
+            assert_matches!(unwind, mir::UnwindAction::Cleanup(_));
             TerminatorEdges::Single(target)
         } else {
             terminator.edges()
diff --git a/compiler/rustc_mir_dataflow/src/lib.rs b/compiler/rustc_mir_dataflow/src/lib.rs
index b0808ba2067e3..8708bebeeb087 100644
--- a/compiler/rustc_mir_dataflow/src/lib.rs
+++ b/compiler/rustc_mir_dataflow/src/lib.rs
@@ -1,4 +1,5 @@
 // tidy-alphabetical-start
+#![feature(assert_matches)]
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]
 #![feature(exact_size_is_empty)]
diff --git a/compiler/rustc_mir_dataflow/src/value_analysis.rs b/compiler/rustc_mir_dataflow/src/value_analysis.rs
index ca8a2777045f4..139fd592f69a3 100644
--- a/compiler/rustc_mir_dataflow/src/value_analysis.rs
+++ b/compiler/rustc_mir_dataflow/src/value_analysis.rs
@@ -32,6 +32,7 @@
 //! Because of that, we can assume that the only way to change the value behind a tracked place is
 //! by direct assignment.
 
+use std::assert_matches::assert_matches;
 use std::fmt::{Debug, Formatter};
 use std::ops::Range;
 
@@ -54,7 +55,7 @@ use crate::{Analysis, AnalysisDomain, JoinSemiLattice, SwitchIntEdgeEffects};
 
 pub trait ValueAnalysis<'tcx> {
     /// For each place of interest, the analysis tracks a value of the given type.
-    type Value: Clone + JoinSemiLattice + HasBottom + HasTop;
+    type Value: Clone + JoinSemiLattice + HasBottom + HasTop + Debug;
 
     const NAME: &'static str;
 
@@ -344,7 +345,7 @@ impl<'tcx, T: ValueAnalysis<'tcx>> AnalysisDomain<'tcx> for ValueAnalysisWrapper
 
     fn initialize_start_block(&self, body: &Body<'tcx>, state: &mut Self::Domain) {
         // The initial state maps all tracked places of argument projections to ⊤ and the rest to ⊥.
-        assert!(matches!(state, State::Unreachable));
+        assert_matches!(state, State::Unreachable);
         *state = State::new_reachable();
         for arg in body.args_iter() {
             state.flood(PlaceRef { local: arg, projection: &[] }, self.0.map());
diff --git a/compiler/rustc_mir_transform/src/promote_consts.rs b/compiler/rustc_mir_transform/src/promote_consts.rs
index dc8e50ac8cd28..48a3266ae6f0d 100644
--- a/compiler/rustc_mir_transform/src/promote_consts.rs
+++ b/compiler/rustc_mir_transform/src/promote_consts.rs
@@ -468,7 +468,7 @@ impl<'tcx> Validator<'_, 'tcx> {
 
                 if let ty::RawPtr(_, _) | ty::FnPtr(..) = lhs_ty.kind() {
                     // Raw and fn pointer operations are not allowed inside consts and thus not promotable.
-                    assert!(matches!(
+                    assert_matches!(
                         op,
                         BinOp::Eq
                             | BinOp::Ne
@@ -477,7 +477,7 @@ impl<'tcx> Validator<'_, 'tcx> {
                             | BinOp::Ge
                             | BinOp::Gt
                             | BinOp::Offset
-                    ));
+                    );
                     return Err(Unpromotable);
                 }
 
diff --git a/compiler/rustc_mir_transform/src/shim.rs b/compiler/rustc_mir_transform/src/shim.rs
index f41f3ef656c51..29185e79bce88 100644
--- a/compiler/rustc_mir_transform/src/shim.rs
+++ b/compiler/rustc_mir_transform/src/shim.rs
@@ -996,7 +996,7 @@ pub fn build_adt_ctor(tcx: TyCtxt<'_>, ctor_id: DefId) -> Body<'_> {
 /// }
 /// ```
 fn build_fn_ptr_addr_shim<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, self_ty: Ty<'tcx>) -> Body<'tcx> {
-    assert!(matches!(self_ty.kind(), ty::FnPtr(..)), "expected fn ptr, found {self_ty}");
+    assert_matches!(self_ty.kind(), ty::FnPtr(..), "expected fn ptr, found {self_ty}");
     let span = tcx.def_span(def_id);
     let Some(sig) = tcx.fn_sig(def_id).instantiate(tcx, &[self_ty.into()]).no_bound_vars() else {
         span_bug!(span, "FnPtr::addr with bound vars for `{self_ty}`");
diff --git a/compiler/rustc_parse/src/lib.rs b/compiler/rustc_parse/src/lib.rs
index e6b04080c8d85..370792714936a 100644
--- a/compiler/rustc_parse/src/lib.rs
+++ b/compiler/rustc_parse/src/lib.rs
@@ -5,6 +5,7 @@
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
 #![feature(array_windows)]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(debug_closure_helpers)]
 #![feature(if_let_guard)]
diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs
index 4b8e4c25e16c2..b7dc21bfc0775 100644
--- a/compiler/rustc_parse/src/parser/mod.rs
+++ b/compiler/rustc_parse/src/parser/mod.rs
@@ -10,6 +10,7 @@ mod path;
 mod stmt;
 mod ty;
 
+use std::assert_matches::debug_assert_matches;
 use std::ops::Range;
 use std::{fmt, mem, slice};
 
@@ -1385,7 +1386,7 @@ impl<'a> Parser<'a> {
                     // can capture these tokens if necessary.
                     self.bump();
                     if self.token_cursor.stack.len() == target_depth {
-                        debug_assert!(matches!(self.token.kind, token::CloseDelim(_)));
+                        debug_assert_matches!(self.token.kind, token::CloseDelim(_));
                         break;
                     }
                 }
diff --git a/compiler/rustc_parse/src/parser/tests.rs b/compiler/rustc_parse/src/parser/tests.rs
index 2d82742f66c02..cb8e8d309887b 100644
--- a/compiler/rustc_parse/src/parser/tests.rs
+++ b/compiler/rustc_parse/src/parser/tests.rs
@@ -1,3 +1,4 @@
+use std::assert_matches::assert_matches;
 use std::io::prelude::*;
 use std::iter::Peekable;
 use std::path::{Path, PathBuf};
@@ -1747,7 +1748,7 @@ fn out_of_line_mod() {
         .unwrap();
 
         let ast::ItemKind::Mod(_, mod_kind) = &item.kind else { panic!() };
-        assert!(matches!(mod_kind, ast::ModKind::Loaded(items, ..) if items.len() == 2));
+        assert_matches!(mod_kind, ast::ModKind::Loaded(items, ..) if items.len() == 2);
     });
 }
 
diff --git a/compiler/rustc_passes/messages.ftl b/compiler/rustc_passes/messages.ftl
index 59c9d1e49f5b3..0318d34fb7322 100644
--- a/compiler/rustc_passes/messages.ftl
+++ b/compiler/rustc_passes/messages.ftl
@@ -223,6 +223,9 @@ passes_doc_masked_only_extern_crate =
     .not_an_extern_crate_label = not an `extern crate` item
     .note = read <https://doc.rust-lang.org/unstable-book/language-features/doc-masked.html> for more information
 
+passes_doc_rust_logo =
+    the `#[doc(rust_logo)]` attribute is used for Rust branding
+
 passes_doc_test_literal = `#![doc(test(...)]` does not take a literal
 
 passes_doc_test_takes_list =
@@ -595,6 +598,9 @@ passes_remove_fields =
      *[other] fields
     }
 
+passes_repr_align_function =
+    `repr(align)` attributes on functions are unstable
+
 passes_repr_conflicting =
     conflicting representation hints
 
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
index 2a63ecfe65877..bd157d1d61973 100644
--- a/compiler/rustc_passes/src/check_attr.rs
+++ b/compiler/rustc_passes/src/check_attr.rs
@@ -1142,7 +1142,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
     /// of one item. Read the documentation of [`check_doc_inline`] for more information.
     ///
     /// [`check_doc_inline`]: Self::check_doc_inline
-    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn check_doc_attrs(
         &self,
         attr: &Attribute,
@@ -1220,7 +1219,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                                     &self.tcx.sess,
                                     sym::rustdoc_internals,
                                     meta.span(),
-                                    "the `#[doc(rust_logo)]` attribute is used for Rust branding",
+                                    fluent::passes_doc_rust_logo,
                                 )
                                 .emit();
                             }
@@ -1736,7 +1735,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
     }
 
     /// Checks if the `#[repr]` attributes on `item` are valid.
-    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn check_repr(
         &self,
         attrs: &[Attribute],
@@ -1793,7 +1791,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                             &self.tcx.sess,
                             sym::fn_align,
                             hint.span(),
-                            "`repr(align)` attributes on functions are unstable",
+                            fluent::passes_repr_align_function,
                         )
                         .emit();
                     }
diff --git a/compiler/rustc_passes/src/entry.rs b/compiler/rustc_passes/src/entry.rs
index 48f55d4c3a0d5..ecb345bb51a49 100644
--- a/compiler/rustc_passes/src/entry.rs
+++ b/compiler/rustc_passes/src/entry.rs
@@ -106,7 +106,6 @@ fn check_and_search_item(id: ItemId, ctxt: &mut EntryContext<'_>) {
     }
 }
 
-#[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
 fn configure_main(tcx: TyCtxt<'_>, visitor: &EntryContext<'_>) -> Option<(DefId, EntryFnType)> {
     if let Some((def_id, _)) = visitor.start_fn {
         Some((def_id.to_def_id(), EntryFnType::Start))
diff --git a/compiler/rustc_target/src/spec/abi/tests.rs b/compiler/rustc_target/src/spec/abi/tests.rs
index 251a12fe7aa6b..4823058dd6970 100644
--- a/compiler/rustc_target/src/spec/abi/tests.rs
+++ b/compiler/rustc_target/src/spec/abi/tests.rs
@@ -1,3 +1,5 @@
+use std::assert_matches::assert_matches;
+
 use super::*;
 
 #[allow(non_snake_case)]
@@ -16,7 +18,7 @@ fn lookup_cdecl() {
 #[test]
 fn lookup_baz() {
     let abi = lookup("baz");
-    assert!(matches!(abi, Err(AbiUnsupported::Unrecognized)))
+    assert_matches!(abi, Err(AbiUnsupported::Unrecognized));
 }
 
 #[test]
diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs
index 95d4509c100a2..f908d8a687006 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs
@@ -687,10 +687,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
         let mut applied_do_not_recommend = false;
         loop {
             if let ObligationCauseCode::ImplDerived(ref c) = base_cause {
-                if self.tcx.has_attrs_with_path(
-                    c.impl_or_alias_def_id,
-                    &[sym::diagnostic, sym::do_not_recommend],
-                ) {
+                if self.tcx.do_not_recommend_impl(c.impl_or_alias_def_id) {
                     let code = (*c.derived.parent_code).clone();
                     obligation.cause.map_code(|_| code);
                     obligation.predicate = c.derived.parent_trait_pred.upcast(self.tcx);
@@ -1629,11 +1626,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                 .tcx
                 .all_impls(def_id)
                 // ignore `do_not_recommend` items
-                .filter(|def_id| {
-                    !self
-                        .tcx
-                        .has_attrs_with_path(*def_id, &[sym::diagnostic, sym::do_not_recommend])
-                })
+                .filter(|def_id| !self.tcx.do_not_recommend_impl(*def_id))
                 // Ignore automatically derived impls and `!Trait` impls.
                 .filter_map(|def_id| self.tcx.impl_trait_header(def_id))
                 .filter_map(|header| {
@@ -1903,12 +1896,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
         let impl_candidates = impl_candidates
             .into_iter()
             .cloned()
-            .filter(|cand| {
-                !self.tcx.has_attrs_with_path(
-                    cand.impl_def_id,
-                    &[sym::diagnostic, sym::do_not_recommend],
-                )
-            })
+            .filter(|cand| !self.tcx.do_not_recommend_impl(cand.impl_def_id))
             .collect::<Vec<_>>();
 
         let def_id = trait_ref.def_id();
diff --git a/compiler/rustc_trait_selection/src/solve/fulfill.rs b/compiler/rustc_trait_selection/src/solve/fulfill.rs
index 49fa775a0a191..de8951ef72046 100644
--- a/compiler/rustc_trait_selection/src/solve/fulfill.rs
+++ b/compiler/rustc_trait_selection/src/solve/fulfill.rs
@@ -13,7 +13,6 @@ use rustc_middle::bug;
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_next_trait_solver::solve::{GenerateProofTree, SolverDelegateEvalExt as _};
-use rustc_span::symbol::sym;
 
 use super::delegate::SolverDelegate;
 use super::inspect::{self, ProofTreeInferCtxtExt, ProofTreeVisitor};
@@ -440,10 +439,7 @@ impl<'tcx> ProofTreeVisitor<'tcx> for BestObligation<'tcx> {
             source: CandidateSource::Impl(impl_def_id),
             result: _,
         } = candidate.kind()
-            && goal
-                .infcx()
-                .tcx
-                .has_attrs_with_path(impl_def_id, &[sym::diagnostic, sym::do_not_recommend])
+            && goal.infcx().tcx.do_not_recommend_impl(impl_def_id)
         {
             return ControlFlow::Break(self.obligation.clone());
         }
diff --git a/compiler/rustc_trait_selection/src/solve/inspect/analyse.rs b/compiler/rustc_trait_selection/src/solve/inspect/analyse.rs
index e8de8457440ff..1a459aa484ff1 100644
--- a/compiler/rustc_trait_selection/src/solve/inspect/analyse.rs
+++ b/compiler/rustc_trait_selection/src/solve/inspect/analyse.rs
@@ -9,6 +9,8 @@
 //! coherence right now and was annoying to implement, so I am leaving it
 //! as is until we start using it for something else.
 
+use std::assert_matches::assert_matches;
+
 use rustc_ast_ir::try_visit;
 use rustc_ast_ir::visit::VisitorResult;
 use rustc_infer::infer::{DefineOpaqueTypes, InferCtxt, InferOk};
@@ -273,10 +275,10 @@ impl<'a, 'tcx> InspectGoal<'a, 'tcx> {
                     steps.push(step)
                 }
                 inspect::ProbeStep::MakeCanonicalResponse { shallow_certainty: c } => {
-                    assert!(matches!(
+                    assert_matches!(
                         shallow_certainty.replace(c),
                         None | Some(Certainty::Maybe(MaybeCause::Ambiguity))
-                    ));
+                    );
                 }
                 inspect::ProbeStep::NestedProbe(ref probe) => {
                     match probe.kind {
diff --git a/compiler/rustc_trait_selection/src/solve/normalize.rs b/compiler/rustc_trait_selection/src/solve/normalize.rs
index 419d7e704dee3..c93c40b482680 100644
--- a/compiler/rustc_trait_selection/src/solve/normalize.rs
+++ b/compiler/rustc_trait_selection/src/solve/normalize.rs
@@ -1,3 +1,4 @@
+use std::assert_matches::assert_matches;
 use std::fmt::Debug;
 use std::marker::PhantomData;
 
@@ -63,7 +64,7 @@ where
     E: FromSolverError<'tcx, NextSolverError<'tcx>>,
 {
     fn normalize_alias_ty(&mut self, alias_ty: Ty<'tcx>) -> Result<Ty<'tcx>, Vec<E>> {
-        assert!(matches!(alias_ty.kind(), ty::Alias(..)));
+        assert_matches!(alias_ty.kind(), ty::Alias(..));
 
         let infcx = self.at.infcx;
         let tcx = infcx.tcx;
diff --git a/compiler/rustc_trait_selection/src/traits/misc.rs b/compiler/rustc_trait_selection/src/traits/misc.rs
index 9a127e752a61a..3e65194577e0d 100644
--- a/compiler/rustc_trait_selection/src/traits/misc.rs
+++ b/compiler/rustc_trait_selection/src/traits/misc.rs
@@ -1,5 +1,7 @@
 //! Miscellaneous type-system utilities that are too small to deserve their own modules.
 
+use std::assert_matches::assert_matches;
+
 use hir::LangItem;
 use rustc_ast::Mutability;
 use rustc_data_structures::fx::FxIndexSet;
@@ -92,7 +94,7 @@ pub fn type_allowed_to_implement_const_param_ty<'tcx>(
     lang_item: LangItem,
     parent_cause: ObligationCause<'tcx>,
 ) -> Result<(), ConstParamTyImplementationError<'tcx>> {
-    assert!(matches!(lang_item, LangItem::ConstParamTy | LangItem::UnsizedConstParamTy));
+    assert_matches!(lang_item, LangItem::ConstParamTy | LangItem::UnsizedConstParamTy);
 
     let inner_tys: Vec<_> = match *self_type.kind() {
         // Trivially okay as these types are all:
diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs
index 4b62a5c59b2f0..8a17d7ed64184 100644
--- a/compiler/rustc_trait_selection/src/traits/project.rs
+++ b/compiler/rustc_trait_selection/src/traits/project.rs
@@ -1110,7 +1110,7 @@ fn assemble_candidates_from_impls<'cx, 'tcx>(
                         | ty::Error(_) => false,
                     }
                 } else if tcx.is_lang_item(trait_ref.def_id, LangItem::PointeeTrait) {
-                    let tail = selcx.tcx().struct_tail_with_normalize(
+                    let tail = selcx.tcx().struct_tail_raw(
                         self_ty,
                         |ty| {
                             // We throw away any obligations we get from this, since we normalize
@@ -1149,10 +1149,10 @@ fn assemble_candidates_from_impls<'cx, 'tcx>(
                         | ty::Never
                         // Extern types have unit metadata, according to RFC 2850
                         | ty::Foreign(_)
-                        // If returned by `struct_tail_without_normalization` this is a unit struct
+                        // If returned by `struct_tail` this is a unit struct
                         // without any fields, or not a struct, and therefore is Sized.
                         | ty::Adt(..)
-                        // If returned by `struct_tail_without_normalization` this is the empty tuple.
+                        // If returned by `struct_tail` this is the empty tuple.
                         | ty::Tuple(..)
                         // Integers and floats are always Sized, and so have unit type metadata.
                         | ty::Infer(ty::InferTy::IntVar(_) | ty::InferTy::FloatVar(..)) => true,
diff --git a/compiler/rustc_ty_utils/src/layout.rs b/compiler/rustc_ty_utils/src/layout.rs
index 1eb03fc3bd6a1..244a6afcf979a 100644
--- a/compiler/rustc_ty_utils/src/layout.rs
+++ b/compiler/rustc_ty_utils/src/layout.rs
@@ -219,9 +219,13 @@ fn layout_of_uncached<'tcx>(
                             // its struct tail cannot be normalized either, so try to get a
                             // more descriptive layout error here, which will lead to less confusing
                             // diagnostics.
+                            //
+                            // We use the raw struct tail function here to get the first tail
+                            // that is an alias, which is likely the cause of the normalization
+                            // error.
                             match tcx.try_normalize_erasing_regions(
                                 param_env,
-                                tcx.struct_tail_without_normalization(pointee),
+                                tcx.struct_tail_raw(pointee, |ty| ty, || {}),
                             ) {
                                 Ok(_) => {}
                                 Err(better_err) => {
diff --git a/compiler/rustc_ty_utils/src/layout_sanity_check.rs b/compiler/rustc_ty_utils/src/layout_sanity_check.rs
index d8e0443c50b85..2223aca28d1f6 100644
--- a/compiler/rustc_ty_utils/src/layout_sanity_check.rs
+++ b/compiler/rustc_ty_utils/src/layout_sanity_check.rs
@@ -249,7 +249,7 @@ pub(super) fn sanity_check_layout<'tcx>(
     if let Variants::Multiple { variants, .. } = &layout.variants {
         for variant in variants.iter() {
             // No nested "multiple".
-            assert!(matches!(variant.variants, Variants::Single { .. }));
+            assert_matches!(variant.variants, Variants::Single { .. });
             // Variants should have the same or a smaller size as the full thing,
             // and same for alignment.
             if variant.size > layout.size {
diff --git a/src/bootstrap/src/bin/main.rs b/src/bootstrap/src/bin/main.rs
index dc8b5487a61e8..f03f03e2d9398 100644
--- a/src/bootstrap/src/bin/main.rs
+++ b/src/bootstrap/src/bin/main.rs
@@ -11,13 +11,19 @@ use std::str::FromStr;
 use std::{env, process};
 
 use bootstrap::{
-    find_recent_config_change_ids, human_readable_changes, t, Build, Config, Subcommand,
+    find_recent_config_change_ids, human_readable_changes, t, Build, Config, Flags, Subcommand,
     CONFIG_CHANGE_HISTORY,
 };
 
 fn main() {
     let args = env::args().skip(1).collect::<Vec<_>>();
-    let config = Config::parse(&args);
+
+    if Flags::try_parse_verbose_help(&args) {
+        return;
+    }
+
+    let flags = Flags::parse(&args);
+    let config = Config::parse(flags);
 
     let mut build_lock;
     let _build_lock_guard;
diff --git a/src/bootstrap/src/core/builder/tests.rs b/src/bootstrap/src/core/builder/tests.rs
index f19a4dd6d490f..e06df65c1bc9d 100644
--- a/src/bootstrap/src/core/builder/tests.rs
+++ b/src/bootstrap/src/core/builder/tests.rs
@@ -3,13 +3,14 @@ use std::thread;
 use super::*;
 use crate::core::build_steps::doc::DocumentationFormat;
 use crate::core::config::Config;
+use crate::Flags;
 
 fn configure(cmd: &str, host: &[&str], target: &[&str]) -> Config {
     configure_with_args(&[cmd.to_owned()], host, target)
 }
 
 fn configure_with_args(cmd: &[String], host: &[&str], target: &[&str]) -> Config {
-    let mut config = Config::parse(cmd);
+    let mut config = Config::parse(Flags::parse(cmd));
     // don't save toolstates
     config.save_toolstates = None;
     config.dry_run = DryRun::SelfCheck;
@@ -23,7 +24,7 @@ fn configure_with_args(cmd: &[String], host: &[&str], target: &[&str]) -> Config
     let submodule_build = Build::new(Config {
         // don't include LLVM, so CI doesn't require ninja/cmake to be installed
         rust_codegen_backends: vec![],
-        ..Config::parse(&["check".to_owned()])
+        ..Config::parse(Flags::parse(&["check".to_owned()]))
     });
     submodule_build.require_submodule("src/doc/book", None);
     config.submodules = Some(false);
diff --git a/src/bootstrap/src/core/config/config.rs b/src/bootstrap/src/core/config/config.rs
index 915fcb449e866..35ee4a29c6822 100644
--- a/src/bootstrap/src/core/config/config.rs
+++ b/src/bootstrap/src/core/config/config.rs
@@ -1191,7 +1191,7 @@ impl Config {
         }
     }
 
-    pub fn parse(args: &[String]) -> Config {
+    pub fn parse(flags: Flags) -> Config {
         #[cfg(test)]
         fn get_toml(_: &Path) -> TomlConfig {
             TomlConfig::default()
@@ -1221,11 +1221,10 @@ impl Config {
                     exit!(2);
                 })
         }
-        Self::parse_inner(args, get_toml)
+        Self::parse_inner(flags, get_toml)
     }
 
-    pub(crate) fn parse_inner(args: &[String], get_toml: impl Fn(&Path) -> TomlConfig) -> Config {
-        let mut flags = Flags::parse(args);
+    pub(crate) fn parse_inner(mut flags: Flags, get_toml: impl Fn(&Path) -> TomlConfig) -> Config {
         let mut config = Config::default_opts();
 
         // Set flags.
diff --git a/src/bootstrap/src/core/config/flags.rs b/src/bootstrap/src/core/config/flags.rs
index 19f752da81c13..3948fe0d98c86 100644
--- a/src/bootstrap/src/core/config/flags.rs
+++ b/src/bootstrap/src/core/config/flags.rs
@@ -183,9 +183,9 @@ pub struct Flags {
 }
 
 impl Flags {
-    pub fn parse(args: &[String]) -> Self {
-        let first = String::from("x.py");
-        let it = std::iter::once(&first).chain(args.iter());
+    /// Check if `<cmd> -h -v` was passed.
+    /// If yes, print the available paths and return `true`.
+    pub fn try_parse_verbose_help(args: &[String]) -> bool {
         // We need to check for `<cmd> -h -v`, in which case we list the paths
         #[derive(Parser)]
         #[command(disable_help_flag(true))]
@@ -198,10 +198,10 @@ impl Flags {
             cmd: Kind,
         }
         if let Ok(HelpVerboseOnly { help: true, verbose: 1.., cmd: subcommand }) =
-            HelpVerboseOnly::try_parse_from(it.clone())
+            HelpVerboseOnly::try_parse_from(normalize_args(args))
         {
             println!("NOTE: updating submodules before printing available paths");
-            let config = Config::parse(&[String::from("build")]);
+            let config = Config::parse(Self::parse(&[String::from("build")]));
             let build = Build::new(config);
             let paths = Builder::get_help(&build, subcommand);
             if let Some(s) = paths {
@@ -209,13 +209,23 @@ impl Flags {
             } else {
                 panic!("No paths available for subcommand `{}`", subcommand.as_str());
             }
-            crate::exit!(0);
+            true
+        } else {
+            false
         }
+    }
 
-        Flags::parse_from(it)
+    pub fn parse(args: &[String]) -> Self {
+        Flags::parse_from(normalize_args(args))
     }
 }
 
+fn normalize_args(args: &[String]) -> Vec<String> {
+    let first = String::from("x.py");
+    let it = std::iter::once(first).chain(args.iter().cloned());
+    it.collect()
+}
+
 #[derive(Debug, Clone, Default, clap::Subcommand)]
 pub enum Subcommand {
     #[command(aliases = ["b"], long_about = "\n
diff --git a/src/bootstrap/src/core/config/mod.rs b/src/bootstrap/src/core/config/mod.rs
index 23556e8bc5d38..9f09dd13f2985 100644
--- a/src/bootstrap/src/core/config/mod.rs
+++ b/src/bootstrap/src/core/config/mod.rs
@@ -1,6 +1,6 @@
 #[allow(clippy::module_inception)]
 mod config;
-pub(crate) mod flags;
+pub mod flags;
 #[cfg(test)]
 mod tests;
 
diff --git a/src/bootstrap/src/core/config/tests.rs b/src/bootstrap/src/core/config/tests.rs
index 6e695d269cf2c..40f3e5e7222fa 100644
--- a/src/bootstrap/src/core/config/tests.rs
+++ b/src/bootstrap/src/core/config/tests.rs
@@ -12,9 +12,10 @@ use crate::core::build_steps::clippy::get_clippy_rules_in_order;
 use crate::core::config::{LldMode, Target, TargetSelection, TomlConfig};
 
 fn parse(config: &str) -> Config {
-    Config::parse_inner(&["check".to_string(), "--config=/does/not/exist".to_string()], |&_| {
-        toml::from_str(&config).unwrap()
-    })
+    Config::parse_inner(
+        Flags::parse(&["check".to_string(), "--config=/does/not/exist".to_string()]),
+        |&_| toml::from_str(&config).unwrap(),
+    )
 }
 
 #[test]
@@ -108,7 +109,7 @@ fn clap_verify() {
 #[test]
 fn override_toml() {
     let config = Config::parse_inner(
-        &[
+        Flags::parse(&[
             "check".to_owned(),
             "--config=/does/not/exist".to_owned(),
             "--set=change-id=1".to_owned(),
@@ -121,7 +122,7 @@ fn override_toml() {
             "--set=target.x86_64-unknown-linux-gnu.rpath=false".to_owned(),
             "--set=target.aarch64-unknown-linux-gnu.sanitizers=false".to_owned(),
             "--set=target.aarch64-apple-darwin.runner=apple".to_owned(),
-        ],
+        ]),
         |&_| {
             toml::from_str(
                 r#"
@@ -201,12 +202,12 @@ runner = "x86_64-runner"
 #[should_panic]
 fn override_toml_duplicate() {
     Config::parse_inner(
-        &[
+        Flags::parse(&[
             "check".to_owned(),
             "--config=/does/not/exist".to_string(),
             "--set=change-id=1".to_owned(),
             "--set=change-id=2".to_owned(),
-        ],
+        ]),
         |&_| toml::from_str("change-id = 0").unwrap(),
     );
 }
@@ -226,7 +227,7 @@ fn profile_user_dist() {
             .and_then(|table: toml::Value| TomlConfig::deserialize(table))
             .unwrap()
     }
-    Config::parse_inner(&["check".to_owned()], get_toml);
+    Config::parse_inner(Flags::parse(&["check".to_owned()]), get_toml);
 }
 
 #[test]
@@ -301,7 +302,7 @@ fn order_of_clippy_rules() {
         "-Aclippy::foo1".to_string(),
         "-Aclippy::foo2".to_string(),
     ];
-    let config = Config::parse(&args);
+    let config = Config::parse(Flags::parse(&args));
 
     let actual = match &config.cmd {
         crate::Subcommand::Clippy { allow, deny, warn, forbid, .. } => {
diff --git a/src/bootstrap/src/lib.rs b/src/bootstrap/src/lib.rs
index 2062d435bfc99..e8a61ab4cf58e 100644
--- a/src/bootstrap/src/lib.rs
+++ b/src/bootstrap/src/lib.rs
@@ -43,7 +43,7 @@ mod core;
 mod utils;
 
 pub use core::builder::PathSet;
-pub use core::config::flags::Subcommand;
+pub use core::config::flags::{Flags, Subcommand};
 pub use core::config::Config;
 
 pub use utils::change_tracker::{
diff --git a/src/bootstrap/src/utils/helpers/tests.rs b/src/bootstrap/src/utils/helpers/tests.rs
index f0cb324674fc6..103c4d26a1854 100644
--- a/src/bootstrap/src/utils/helpers/tests.rs
+++ b/src/bootstrap/src/utils/helpers/tests.rs
@@ -5,7 +5,7 @@ use std::path::PathBuf;
 use crate::utils::helpers::{
     check_cfg_arg, extract_beta_rev, hex_encode, make, program_out_of_date, symlink_dir,
 };
-use crate::Config;
+use crate::{Config, Flags};
 
 #[test]
 fn test_make() {
@@ -58,7 +58,8 @@ fn test_check_cfg_arg() {
 
 #[test]
 fn test_program_out_of_date() {
-    let config = Config::parse(&["check".to_owned(), "--config=/does/not/exist".to_owned()]);
+    let config =
+        Config::parse(Flags::parse(&["check".to_owned(), "--config=/does/not/exist".to_owned()]));
     let tempfile = config.tempdir().join(".tmp-stamp-file");
     File::create(&tempfile).unwrap().write_all(b"dummy value").unwrap();
     assert!(tempfile.exists());
@@ -73,7 +74,8 @@ fn test_program_out_of_date() {
 
 #[test]
 fn test_symlink_dir() {
-    let config = Config::parse(&["check".to_owned(), "--config=/does/not/exist".to_owned()]);
+    let config =
+        Config::parse(Flags::parse(&["check".to_owned(), "--config=/does/not/exist".to_owned()]));
     let tempdir = config.tempdir().join(".tmp-dir");
     let link_path = config.tempdir().join(".tmp-link");
 
diff --git a/src/tools/run-make-support/src/external_deps/llvm.rs b/src/tools/run-make-support/src/external_deps/llvm.rs
index dc651fdd8205a..4003287d7629d 100644
--- a/src/tools/run-make-support/src/external_deps/llvm.rs
+++ b/src/tools/run-make-support/src/external_deps/llvm.rs
@@ -271,6 +271,12 @@ impl LlvmAr {
         self
     }
 
+    /// Like `obj_to_ar` except creating a thin archive.
+    pub fn obj_to_thin_ar(&mut self) -> &mut Self {
+        self.cmd.arg("rcus").arg("--thin");
+        self
+    }
+
     /// Extract archive members back to files.
     pub fn extract(&mut self) -> &mut Self {
         self.cmd.arg("x");
diff --git a/tests/run-make/CURRENT_RUSTC_VERSION/rmake.rs b/tests/run-make/CURRENT_RUSTC_VERSION/rmake.rs
index fec4a4bb90b36..024ce975cd63a 100644
--- a/tests/run-make/CURRENT_RUSTC_VERSION/rmake.rs
+++ b/tests/run-make/CURRENT_RUSTC_VERSION/rmake.rs
@@ -3,8 +3,6 @@
 // Check that the `CURRENT_RUSTC_VERSION` placeholder is correctly replaced by the current
 // `rustc` version and the `since` property in feature stability gating is properly respected.
 
-use std::path::PathBuf;
-
 use run_make_support::{aux_build, rfs, rustc, source_root};
 
 fn main() {
diff --git a/tests/run-make/arguments-non-c-like-enum/rmake.rs b/tests/run-make/arguments-non-c-like-enum/rmake.rs
index 036691e850931..f8e077e0a79f7 100644
--- a/tests/run-make/arguments-non-c-like-enum/rmake.rs
+++ b/tests/run-make/arguments-non-c-like-enum/rmake.rs
@@ -4,8 +4,6 @@
 use run_make_support::{cc, extra_c_flags, extra_cxx_flags, run, rustc, static_lib_name};
 
 pub fn main() {
-    use std::path::Path;
-
     rustc().input("nonclike.rs").crate_type("staticlib").run();
     cc().input("test.c")
         .input(static_lib_name("nonclike"))
diff --git a/tests/run-make/c-link-to-rust-staticlib/rmake.rs b/tests/run-make/c-link-to-rust-staticlib/rmake.rs
index e21b976035bc1..6d045012e95fb 100644
--- a/tests/run-make/c-link-to-rust-staticlib/rmake.rs
+++ b/tests/run-make/c-link-to-rust-staticlib/rmake.rs
@@ -3,8 +3,6 @@
 
 //@ ignore-cross-compile
 
-use std::fs;
-
 use run_make_support::rfs::remove_file;
 use run_make_support::{cc, extra_c_flags, run, rustc, static_lib_name};
 
diff --git a/tests/run-make/comment-section/rmake.rs b/tests/run-make/comment-section/rmake.rs
index ecee441b35f66..1557f50dbd024 100644
--- a/tests/run-make/comment-section/rmake.rs
+++ b/tests/run-make/comment-section/rmake.rs
@@ -7,9 +7,7 @@
 // FIXME(jieyouxu): check cross-compile setup
 //@ ignore-cross-compile
 
-use std::path::PathBuf;
-
-use run_make_support::{cwd, env_var, llvm_readobj, rfs, run_in_tmpdir, rustc};
+use run_make_support::{cwd, env_var, llvm_readobj, rfs, rustc};
 
 fn main() {
     let target = env_var("TARGET");
diff --git a/tests/run-make/compressed-debuginfo/rmake.rs b/tests/run-make/compressed-debuginfo/rmake.rs
index 3a656f28c2241..5ba1a1852d51b 100644
--- a/tests/run-make/compressed-debuginfo/rmake.rs
+++ b/tests/run-make/compressed-debuginfo/rmake.rs
@@ -5,7 +5,7 @@
 
 // FIXME: This test isn't comprehensive and isn't covering all possible combinations.
 
-use run_make_support::{assert_contains, cmd, llvm_readobj, run_in_tmpdir, rustc};
+use run_make_support::{assert_contains, llvm_readobj, run_in_tmpdir, rustc};
 
 fn check_compression(compression: &str, to_find: &str) {
     run_in_tmpdir(|| {
diff --git a/tests/run-make/const_fn_mir/rmake.rs b/tests/run-make/const_fn_mir/rmake.rs
index 1ba93421855d3..0c33b1ce34ef9 100644
--- a/tests/run-make/const_fn_mir/rmake.rs
+++ b/tests/run-make/const_fn_mir/rmake.rs
@@ -2,7 +2,7 @@
 
 //@ needs-unwind
 
-use run_make_support::{cwd, diff, rustc};
+use run_make_support::{diff, rustc};
 
 fn main() {
     rustc().input("main.rs").emit("mir").output("dump-actual.mir").run();
diff --git a/tests/run-make/crate-loading/rmake.rs b/tests/run-make/crate-loading/rmake.rs
index fd5b66ae87934..d7abd5872c94a 100644
--- a/tests/run-make/crate-loading/rmake.rs
+++ b/tests/run-make/crate-loading/rmake.rs
@@ -2,14 +2,13 @@
 //@ ignore-wasm32
 //@ ignore-wasm64
 
-use run_make_support::rfs::copy;
-use run_make_support::{assert_contains, rust_lib_name, rustc};
+use run_make_support::{rust_lib_name, rustc};
 
 fn main() {
     rustc().input("multiple-dep-versions-1.rs").run();
     rustc().input("multiple-dep-versions-2.rs").extra_filename("2").metadata("2").run();
 
-    let out = rustc()
+    rustc()
         .input("multiple-dep-versions.rs")
         .extern_("dependency", rust_lib_name("dependency"))
         .extern_("dep_2_reexport", rust_lib_name("dependency2"))
diff --git a/tests/run-make/dylib-soname/rmake.rs b/tests/run-make/dylib-soname/rmake.rs
index a0215a6906e47..cec0d46384246 100644
--- a/tests/run-make/dylib-soname/rmake.rs
+++ b/tests/run-make/dylib-soname/rmake.rs
@@ -4,7 +4,6 @@
 //@ only-linux
 //@ ignore-cross-compile
 
-use run_make_support::regex::Regex;
 use run_make_support::{cmd, run_in_tmpdir, rustc};
 
 fn main() {
diff --git a/tests/run-make/extern-flag-disambiguates/rmake.rs b/tests/run-make/extern-flag-disambiguates/rmake.rs
index 2d7d7f69f66fa..89cda02eaeae6 100644
--- a/tests/run-make/extern-flag-disambiguates/rmake.rs
+++ b/tests/run-make/extern-flag-disambiguates/rmake.rs
@@ -1,6 +1,6 @@
 //@ ignore-cross-compile
 
-use run_make_support::{cwd, run, rustc};
+use run_make_support::{run, rustc};
 
 // Attempt to build this dependency tree:
 //
diff --git a/tests/run-make/ice-dep-cannot-find-dep/rmake.rs b/tests/run-make/ice-dep-cannot-find-dep/rmake.rs
index 8ba3a0366b002..1c136773f0155 100644
--- a/tests/run-make/ice-dep-cannot-find-dep/rmake.rs
+++ b/tests/run-make/ice-dep-cannot-find-dep/rmake.rs
@@ -16,7 +16,7 @@
 //       If we used `rustc` the additional '-L rmake_out' option would allow rustc to
 //       actually find the crate.
 
-use run_make_support::{bare_rustc, rfs, rust_lib_name, rustc};
+use run_make_support::{bare_rustc, rust_lib_name, rustc};
 
 fn main() {
     rustc().crate_name("a").crate_type("rlib").input("a.rs").arg("--verbose").run();
diff --git a/tests/run-make/incr-test-moved-file/rmake.rs b/tests/run-make/incr-test-moved-file/rmake.rs
index f314e110a8c33..0ba1b0d58feeb 100644
--- a/tests/run-make/incr-test-moved-file/rmake.rs
+++ b/tests/run-make/incr-test-moved-file/rmake.rs
@@ -14,7 +14,7 @@
 //@ ignore-nvptx64-nvidia-cuda
 // FIXME: can't find crate for 'std'
 
-use run_make_support::{rfs, rust_lib_name, rustc};
+use run_make_support::{rfs, rustc};
 
 fn main() {
     rfs::create_dir("incr");
diff --git a/tests/run-make/incremental-debugger-visualizer/rmake.rs b/tests/run-make/incremental-debugger-visualizer/rmake.rs
index 58a7e415bc58b..07c920cc04a6f 100644
--- a/tests/run-make/incremental-debugger-visualizer/rmake.rs
+++ b/tests/run-make/incremental-debugger-visualizer/rmake.rs
@@ -2,8 +2,6 @@
 // (in this case, foo.py and foo.natvis) are picked up when compiling incrementally.
 // See https://github.com/rust-lang/rust/pull/111641
 
-use std::io::Read;
-
 use run_make_support::{invalid_utf8_contains, invalid_utf8_not_contains, rfs, rustc};
 
 fn main() {
diff --git a/tests/run-make/lto-readonly-lib/rmake.rs b/tests/run-make/lto-readonly-lib/rmake.rs
index b9f0dc21dafc2..78f2b580e0df2 100644
--- a/tests/run-make/lto-readonly-lib/rmake.rs
+++ b/tests/run-make/lto-readonly-lib/rmake.rs
@@ -7,7 +7,7 @@
 
 //@ ignore-cross-compile
 
-use run_make_support::{rfs, run, rust_lib_name, rustc, test_while_readonly};
+use run_make_support::{run, rust_lib_name, rustc, test_while_readonly};
 
 fn main() {
     rustc().input("lib.rs").run();
diff --git a/tests/run-make/multiple-emits/rmake.rs b/tests/run-make/multiple-emits/rmake.rs
index 67c0ebb9864a5..8a5eb1d9d856a 100644
--- a/tests/run-make/multiple-emits/rmake.rs
+++ b/tests/run-make/multiple-emits/rmake.rs
@@ -1,4 +1,4 @@
-use run_make_support::{cwd, path, rustc};
+use run_make_support::{path, rustc};
 
 fn main() {
     rustc().input("foo.rs").emit("asm,llvm-ir").output("out").run();
diff --git a/tests/run-make/naked-symbol-visibility/rmake.rs b/tests/run-make/naked-symbol-visibility/rmake.rs
index a32e62326eb32..07ff253788d0a 100644
--- a/tests/run-make/naked-symbol-visibility/rmake.rs
+++ b/tests/run-make/naked-symbol-visibility/rmake.rs
@@ -3,7 +3,7 @@
 use run_make_support::object::read::{File, Object, Symbol};
 use run_make_support::object::ObjectSymbol;
 use run_make_support::targets::is_windows;
-use run_make_support::{dynamic_lib_name, env_var, rfs, rustc};
+use run_make_support::{dynamic_lib_name, rfs, rustc};
 
 fn main() {
     let rdylib_name = dynamic_lib_name("a_rust_dylib");
diff --git a/tests/run-make/non-unicode-in-incremental-dir/rmake.rs b/tests/run-make/non-unicode-in-incremental-dir/rmake.rs
index ef316f1103638..42bd4b1b79990 100644
--- a/tests/run-make/non-unicode-in-incremental-dir/rmake.rs
+++ b/tests/run-make/non-unicode-in-incremental-dir/rmake.rs
@@ -8,7 +8,7 @@ fn main() {
     match std::fs::create_dir(&non_unicode) {
         // If an error occurs, check if creating a directory with a valid Unicode name would
         // succeed.
-        Err(e) if std::fs::create_dir("valid_unicode").is_ok() => {
+        Err(_) if std::fs::create_dir("valid_unicode").is_ok() => {
             // Filesystem doesn't appear support non-Unicode paths.
             return;
         }
diff --git a/tests/run-make/output-type-permutations/rmake.rs b/tests/run-make/output-type-permutations/rmake.rs
index 76fd8c1c2603a..c0569af6e84a3 100644
--- a/tests/run-make/output-type-permutations/rmake.rs
+++ b/tests/run-make/output-type-permutations/rmake.rs
@@ -113,7 +113,7 @@ fn main() {
     assert_expected_output_files(
         Expectations {
             expected_files: s!["foo"],
-            allowed_files: s![],
+            allowed_files: vec![],
             test_dir: "asm-emit".to_string(),
         },
         || {
@@ -123,7 +123,7 @@ fn main() {
     assert_expected_output_files(
         Expectations {
             expected_files: s!["foo"],
-            allowed_files: s![],
+            allowed_files: vec![],
             test_dir: "asm-emit2".to_string(),
         },
         || {
@@ -133,7 +133,7 @@ fn main() {
     assert_expected_output_files(
         Expectations {
             expected_files: s!["foo"],
-            allowed_files: s![],
+            allowed_files: vec![],
             test_dir: "asm-emit3".to_string(),
         },
         || {
@@ -144,7 +144,7 @@ fn main() {
     assert_expected_output_files(
         Expectations {
             expected_files: s!["foo"],
-            allowed_files: s![],
+            allowed_files: vec![],
             test_dir: "llvm-ir-emit".to_string(),
         },
         || {
@@ -154,7 +154,7 @@ fn main() {
     assert_expected_output_files(
         Expectations {
             expected_files: s!["foo"],
-            allowed_files: s![],
+            allowed_files: vec![],
             test_dir: "llvm-ir-emit2".to_string(),
         },
         || {
@@ -164,7 +164,7 @@ fn main() {
     assert_expected_output_files(
         Expectations {
             expected_files: s!["foo"],
-            allowed_files: s![],
+            allowed_files: vec![],
             test_dir: "llvm-ir-emit3".to_string(),
         },
         || {
@@ -175,7 +175,7 @@ fn main() {
     assert_expected_output_files(
         Expectations {
             expected_files: s!["foo"],
-            allowed_files: s![],
+            allowed_files: vec![],
             test_dir: "llvm-bc-emit".to_string(),
         },
         || {
@@ -185,7 +185,7 @@ fn main() {
     assert_expected_output_files(
         Expectations {
             expected_files: s!["foo"],
-            allowed_files: s![],
+            allowed_files: vec![],
             test_dir: "llvm-bc-emit2".to_string(),
         },
         || {
@@ -195,7 +195,7 @@ fn main() {
     assert_expected_output_files(
         Expectations {
             expected_files: s!["foo"],
-            allowed_files: s![],
+            allowed_files: vec![],
             test_dir: "llvm-bc-emit3".to_string(),
         },
         || {
@@ -206,7 +206,7 @@ fn main() {
     assert_expected_output_files(
         Expectations {
             expected_files: s!["foo"],
-            allowed_files: s![],
+            allowed_files: vec![],
             test_dir: "obj-emit".to_string(),
         },
         || {
@@ -216,7 +216,7 @@ fn main() {
     assert_expected_output_files(
         Expectations {
             expected_files: s!["foo"],
-            allowed_files: s![],
+            allowed_files: vec![],
             test_dir: "obj-emit2".to_string(),
         },
         || {
@@ -226,7 +226,7 @@ fn main() {
     assert_expected_output_files(
         Expectations {
             expected_files: s!["foo"],
-            allowed_files: s![],
+            allowed_files: vec![],
             test_dir: "obj-emit3".to_string(),
         },
         || {
@@ -268,7 +268,7 @@ fn main() {
     assert_expected_output_files(
         Expectations {
             expected_files: s!["foo"],
-            allowed_files: s![],
+            allowed_files: vec![],
             test_dir: "rlib".to_string(),
         },
         || {
@@ -278,7 +278,7 @@ fn main() {
     assert_expected_output_files(
         Expectations {
             expected_files: s!["foo"],
-            allowed_files: s![],
+            allowed_files: vec![],
             test_dir: "rlib2".to_string(),
         },
         || {
@@ -288,7 +288,7 @@ fn main() {
     assert_expected_output_files(
         Expectations {
             expected_files: s!["foo"],
-            allowed_files: s![],
+            allowed_files: vec![],
             test_dir: "rlib3".to_string(),
         },
         || {
@@ -375,7 +375,7 @@ fn main() {
     assert_expected_output_files(
         Expectations {
             expected_files: s!["foo"],
-            allowed_files: s![],
+            allowed_files: vec![],
             test_dir: "staticlib".to_string(),
         },
         || {
@@ -385,7 +385,7 @@ fn main() {
     assert_expected_output_files(
         Expectations {
             expected_files: s!["foo"],
-            allowed_files: s![],
+            allowed_files: vec![],
             test_dir: "staticlib2".to_string(),
         },
         || {
@@ -395,7 +395,7 @@ fn main() {
     assert_expected_output_files(
         Expectations {
             expected_files: s!["foo"],
-            allowed_files: s![],
+            allowed_files: vec![],
             test_dir: "staticlib3".to_string(),
         },
         || {
@@ -449,7 +449,7 @@ fn main() {
     assert_expected_output_files(
         Expectations {
             expected_files: s!["ir", rust_lib_name("bar")],
-            allowed_files: s![],
+            allowed_files: vec![],
             test_dir: "rlib-ir".to_string(),
         },
         || {
@@ -466,7 +466,7 @@ fn main() {
     assert_expected_output_files(
         Expectations {
             expected_files: s!["ir", "asm", "bc", "obj", "link"],
-            allowed_files: s![],
+            allowed_files: vec![],
             test_dir: "staticlib-all".to_string(),
         },
         || {
@@ -484,7 +484,7 @@ fn main() {
     assert_expected_output_files(
         Expectations {
             expected_files: s!["ir", "asm", "bc", "obj", "link"],
-            allowed_files: s![],
+            allowed_files: vec![],
             test_dir: "staticlib-all2".to_string(),
         },
         || {
@@ -523,7 +523,7 @@ fn main() {
     assert_expected_output_files(
         Expectations {
             expected_files: s!["bar.bc", rust_lib_name("bar"), "foo.bc"],
-            allowed_files: s![],
+            allowed_files: vec![],
             test_dir: "rlib-emits".to_string(),
         },
         || {
diff --git a/tests/run-make/print-check-cfg/rmake.rs b/tests/run-make/print-check-cfg/rmake.rs
index b10336f88c649..f6f7f7cece6e7 100644
--- a/tests/run-make/print-check-cfg/rmake.rs
+++ b/tests/run-make/print-check-cfg/rmake.rs
@@ -4,7 +4,6 @@ extern crate run_make_support;
 
 use std::collections::HashSet;
 use std::iter::FromIterator;
-use std::ops::Deref;
 
 use run_make_support::rustc;
 
diff --git a/tests/run-make/print-native-static-libs/rmake.rs b/tests/run-make/print-native-static-libs/rmake.rs
index b4e7c0e17ff8e..a51ac934c722e 100644
--- a/tests/run-make/print-native-static-libs/rmake.rs
+++ b/tests/run-make/print-native-static-libs/rmake.rs
@@ -12,8 +12,6 @@
 //@ ignore-cross-compile
 //@ ignore-wasm
 
-use std::io::BufRead;
-
 use run_make_support::{is_msvc, rustc};
 
 fn main() {
diff --git a/tests/run-make/redundant-libs/rmake.rs b/tests/run-make/redundant-libs/rmake.rs
index 43bb30bde702d..e984dee8df5ba 100644
--- a/tests/run-make/redundant-libs/rmake.rs
+++ b/tests/run-make/redundant-libs/rmake.rs
@@ -11,9 +11,7 @@
 //@ ignore-cross-compile
 // Reason: the compiled binary is executed
 
-use run_make_support::{
-    build_native_dynamic_lib, build_native_static_lib, cwd, is_msvc, rfs, run, rustc,
-};
+use run_make_support::{build_native_dynamic_lib, build_native_static_lib, run, rustc};
 
 fn main() {
     build_native_dynamic_lib("foo");
diff --git a/tests/run-make/reproducible-build-2/rmake.rs b/tests/run-make/reproducible-build-2/rmake.rs
index c500c4238b088..8b5825cad3026 100644
--- a/tests/run-make/reproducible-build-2/rmake.rs
+++ b/tests/run-make/reproducible-build-2/rmake.rs
@@ -13,7 +13,7 @@
 // 2. When the sysroot gets copied, some symlinks must be re-created,
 // which is a privileged action on Windows.
 
-use run_make_support::{bin_name, rfs, rust_lib_name, rustc};
+use run_make_support::{rfs, rust_lib_name, rustc};
 
 fn main() {
     // test 1: fat lto
diff --git a/tests/run-make/reset-codegen-1/rmake.rs b/tests/run-make/reset-codegen-1/rmake.rs
index d19907a675e02..118b3a666ad86 100644
--- a/tests/run-make/reset-codegen-1/rmake.rs
+++ b/tests/run-make/reset-codegen-1/rmake.rs
@@ -9,7 +9,7 @@
 
 use std::path::Path;
 
-use run_make_support::{bin_name, rfs, rustc};
+use run_make_support::{bin_name, rustc};
 
 fn compile(output_file: &str, emit: Option<&str>) {
     let mut rustc = rustc();
diff --git a/tests/run-make/rlib-format-packed-bundled-libs-3/rmake.rs b/tests/run-make/rlib-format-packed-bundled-libs-3/rmake.rs
index d152047600f0c..67e839bec703d 100644
--- a/tests/run-make/rlib-format-packed-bundled-libs-3/rmake.rs
+++ b/tests/run-make/rlib-format-packed-bundled-libs-3/rmake.rs
@@ -6,7 +6,7 @@
 // See https://github.com/rust-lang/rust/pull/105601
 
 use run_make_support::{
-    build_native_static_lib, is_msvc, llvm_ar, regex, rfs, rust_lib_name, rustc, static_lib_name,
+    build_native_static_lib, llvm_ar, regex, rfs, rust_lib_name, rustc, static_lib_name,
 };
 
 //@ ignore-cross-compile
diff --git a/tests/run-make/run-in-tmpdir-self-test/rmake.rs b/tests/run-make/run-in-tmpdir-self-test/rmake.rs
index 83b99bfe86325..dba036f88669e 100644
--- a/tests/run-make/run-in-tmpdir-self-test/rmake.rs
+++ b/tests/run-make/run-in-tmpdir-self-test/rmake.rs
@@ -3,7 +3,7 @@
 //! when returning from the closure.
 
 use std::fs;
-use std::path::{Path, PathBuf};
+use std::path::PathBuf;
 
 use run_make_support::{cwd, run_in_tmpdir};
 
diff --git a/tests/run-make/rust-lld-by-default-nightly/rmake.rs b/tests/run-make/rust-lld-by-default-nightly/rmake.rs
index 79424984c2139..02bbe8227f032 100644
--- a/tests/run-make/rust-lld-by-default-nightly/rmake.rs
+++ b/tests/run-make/rust-lld-by-default-nightly/rmake.rs
@@ -6,8 +6,6 @@
 //@ ignore-stable
 //@ only-x86_64-unknown-linux-gnu
 
-use std::process::Output;
-
 use run_make_support::regex::Regex;
 use run_make_support::rustc;
 
diff --git a/tests/run-make/rust-lld-compress-debug-sections/rmake.rs b/tests/run-make/rust-lld-compress-debug-sections/rmake.rs
index df9691ccbcf39..ea4997fab8099 100644
--- a/tests/run-make/rust-lld-compress-debug-sections/rmake.rs
+++ b/tests/run-make/rust-lld-compress-debug-sections/rmake.rs
@@ -6,7 +6,7 @@
 
 // FIXME: This test isn't comprehensive and isn't covering all possible combinations.
 
-use run_make_support::{assert_contains, cmd, llvm_readobj, run_in_tmpdir, rustc};
+use run_make_support::{assert_contains, llvm_readobj, run_in_tmpdir, rustc};
 
 fn check_compression(compression: &str, to_find: &str) {
     run_in_tmpdir(|| {
diff --git a/tests/run-make/rust-lld-custom-target/rmake.rs b/tests/run-make/rust-lld-custom-target/rmake.rs
index 17247125521ce..a6f7c33793afe 100644
--- a/tests/run-make/rust-lld-custom-target/rmake.rs
+++ b/tests/run-make/rust-lld-custom-target/rmake.rs
@@ -8,8 +8,6 @@
 //@ needs-rust-lld
 //@ only-x86_64-unknown-linux-gnu
 
-use std::process::Output;
-
 use run_make_support::regex::Regex;
 use run_make_support::rustc;
 
diff --git a/tests/run-make/rust-lld/rmake.rs b/tests/run-make/rust-lld/rmake.rs
index d0bc19130d7cb..1f311af1ed591 100644
--- a/tests/run-make/rust-lld/rmake.rs
+++ b/tests/run-make/rust-lld/rmake.rs
@@ -4,8 +4,6 @@
 //@ needs-rust-lld
 //@ ignore-s390x lld does not yet support s390x as target
 
-use std::process::Output;
-
 use run_make_support::regex::Regex;
 use run_make_support::{is_msvc, rustc};
 
diff --git a/tests/run-make/rustdoc-io-error/rmake.rs b/tests/run-make/rustdoc-io-error/rmake.rs
index d64c5106ffb67..a5fae36e733da 100644
--- a/tests/run-make/rustdoc-io-error/rmake.rs
+++ b/tests/run-make/rustdoc-io-error/rmake.rs
@@ -14,22 +14,20 @@
 // `mkfs.ext4 -d`, as well as mounting a loop device for the rootfs.
 //@ ignore-windows - the `set_readonly` functions doesn't work on folders.
 
-use std::fs;
-
-use run_make_support::{path, rustdoc};
+use run_make_support::{path, rfs, rustdoc};
 
 fn main() {
     let out_dir = path("rustdoc-io-error");
-    let output = fs::create_dir(&out_dir).unwrap();
-    let mut permissions = fs::metadata(&out_dir).unwrap().permissions();
+    rfs::create_dir(&out_dir);
+    let mut permissions = rfs::metadata(&out_dir).permissions();
     let original_permissions = permissions.clone();
 
     permissions.set_readonly(true);
-    fs::set_permissions(&out_dir, permissions).unwrap();
+    rfs::set_permissions(&out_dir, permissions);
 
     let output = rustdoc().input("foo.rs").output(&out_dir).env("RUST_BACKTRACE", "1").run_fail();
 
-    fs::set_permissions(&out_dir, original_permissions).unwrap();
+    rfs::set_permissions(&out_dir, original_permissions);
 
     output
         .assert_exit_code(1)
diff --git a/tests/run-make/rustdoc-scrape-examples-remap/scrape.rs b/tests/run-make/rustdoc-scrape-examples-remap/scrape.rs
index 4badc68845e96..eca07043b557c 100644
--- a/tests/run-make/rustdoc-scrape-examples-remap/scrape.rs
+++ b/tests/run-make/rustdoc-scrape-examples-remap/scrape.rs
@@ -1,6 +1,6 @@
 use std::path::Path;
 
-use run_make_support::{htmldocck, rfs, rustc, rustdoc, source_root};
+use run_make_support::{htmldocck, rfs, rustc, rustdoc};
 
 pub fn scrape(extra_args: &[&str]) {
     let out_dir = Path::new("rustdoc");
diff --git a/tests/run-make/sepcomp-cci-copies/rmake.rs b/tests/run-make/sepcomp-cci-copies/rmake.rs
index e244f54658073..a66cc2872b434 100644
--- a/tests/run-make/sepcomp-cci-copies/rmake.rs
+++ b/tests/run-make/sepcomp-cci-copies/rmake.rs
@@ -4,10 +4,7 @@
 // created for each source module (see `rustc_const_eval::monomorphize::partitioning`).
 // See https://github.com/rust-lang/rust/pull/16367
 
-use run_make_support::{
-    count_regex_matches_in_files_with_extension, cwd, has_extension, regex, rfs, rustc,
-    shallow_find_files,
-};
+use run_make_support::{count_regex_matches_in_files_with_extension, regex, rustc};
 
 fn main() {
     rustc().input("cci_lib.rs").run();
diff --git a/tests/run-make/sepcomp-inlining/rmake.rs b/tests/run-make/sepcomp-inlining/rmake.rs
index b7a6bed05b846..ea4a4d210cc3e 100644
--- a/tests/run-make/sepcomp-inlining/rmake.rs
+++ b/tests/run-make/sepcomp-inlining/rmake.rs
@@ -5,10 +5,7 @@
 // in only one compilation unit.
 // See https://github.com/rust-lang/rust/pull/16367
 
-use run_make_support::{
-    count_regex_matches_in_files_with_extension, cwd, has_extension, regex, rfs, rustc,
-    shallow_find_files,
-};
+use run_make_support::{count_regex_matches_in_files_with_extension, regex, rustc};
 
 fn main() {
     rustc().input("foo.rs").emit("llvm-ir").codegen_units(3).arg("-Zinline-in-all-cgus").run();
diff --git a/tests/run-make/sepcomp-separate/rmake.rs b/tests/run-make/sepcomp-separate/rmake.rs
index 90017572c4c18..49958044a612a 100644
--- a/tests/run-make/sepcomp-separate/rmake.rs
+++ b/tests/run-make/sepcomp-separate/rmake.rs
@@ -3,10 +3,7 @@
 // wind up in three different compilation units.
 // See https://github.com/rust-lang/rust/pull/16367
 
-use run_make_support::{
-    count_regex_matches_in_files_with_extension, cwd, has_extension, regex, rfs, rustc,
-    shallow_find_files,
-};
+use run_make_support::{count_regex_matches_in_files_with_extension, regex, rustc};
 
 fn main() {
     rustc().input("foo.rs").emit("llvm-ir").codegen_units(3).run();
diff --git a/tests/run-make/staticlib-thin-archive/bin.rs b/tests/run-make/staticlib-thin-archive/bin.rs
new file mode 100644
index 0000000000000..97a2751f20bcc
--- /dev/null
+++ b/tests/run-make/staticlib-thin-archive/bin.rs
@@ -0,0 +1,5 @@
+fn main() {
+    unsafe {
+        rust_lib::simple_fn();
+    }
+}
diff --git a/tests/run-make/staticlib-thin-archive/rmake.rs b/tests/run-make/staticlib-thin-archive/rmake.rs
new file mode 100644
index 0000000000000..f7e3e43d53581
--- /dev/null
+++ b/tests/run-make/staticlib-thin-archive/rmake.rs
@@ -0,0 +1,28 @@
+// Regression test for https://github.com/rust-lang/rust/issues/107407 which
+// checks that rustc can read thin archive. Before the object crate added thin
+// archive support rustc would add emit object files to the staticlib and after
+// the object crate added thin archive support it would previously crash the
+// compiler due to a missing special case for thin archive members.
+use std::path::Path;
+
+use run_make_support::{llvm_ar, rust_lib_name, rustc, static_lib_name};
+
+fn main() {
+    std::fs::create_dir("archive").unwrap();
+
+    // Build a thin archive
+    rustc().input("simple_obj.rs").emit("obj").output("archive/simple_obj.o").run();
+    llvm_ar()
+        .obj_to_thin_ar()
+        .output_input(
+            Path::new("archive").join(static_lib_name("thin_archive")),
+            "archive/simple_obj.o",
+        )
+        .run();
+
+    // Build an rlib which includes the members of this thin archive
+    rustc().input("rust_lib.rs").library_search_path("archive").run();
+
+    // Build a binary which requires a symbol from the thin archive
+    rustc().input("bin.rs").extern_("rust_lib", rust_lib_name("rust_lib")).run();
+}
diff --git a/tests/run-make/staticlib-thin-archive/rust_lib.rs b/tests/run-make/staticlib-thin-archive/rust_lib.rs
new file mode 100644
index 0000000000000..c76b0f2543376
--- /dev/null
+++ b/tests/run-make/staticlib-thin-archive/rust_lib.rs
@@ -0,0 +1,6 @@
+#![crate_type = "rlib"]
+
+#[link(name = "thin_archive", kind = "static")]
+extern "C" {
+    pub fn simple_fn();
+}
diff --git a/tests/run-make/staticlib-thin-archive/simple_obj.rs b/tests/run-make/staticlib-thin-archive/simple_obj.rs
new file mode 100644
index 0000000000000..a120c9b3e676b
--- /dev/null
+++ b/tests/run-make/staticlib-thin-archive/simple_obj.rs
@@ -0,0 +1,4 @@
+#![crate_type = "staticlib"]
+
+#[no_mangle]
+extern "C" fn simple_fn() {}
diff --git a/tests/ui/cast/ptr-to-trait-obj-different-regions-id-trait.stderr b/tests/ui/cast/ptr-to-trait-obj-different-regions-id-trait.current.stderr
similarity index 91%
rename from tests/ui/cast/ptr-to-trait-obj-different-regions-id-trait.stderr
rename to tests/ui/cast/ptr-to-trait-obj-different-regions-id-trait.current.stderr
index d1d598e603f18..5a5b4bfcacf43 100644
--- a/tests/ui/cast/ptr-to-trait-obj-different-regions-id-trait.stderr
+++ b/tests/ui/cast/ptr-to-trait-obj-different-regions-id-trait.current.stderr
@@ -1,5 +1,5 @@
 error: lifetime may not live long enough
-  --> $DIR/ptr-to-trait-obj-different-regions-id-trait.rs:21:17
+  --> $DIR/ptr-to-trait-obj-different-regions-id-trait.rs:24:17
    |
 LL | fn m<'a>() {
    |      -- lifetime `'a` defined here
diff --git a/tests/ui/cast/ptr-to-trait-obj-different-regions-id-trait.next.stderr b/tests/ui/cast/ptr-to-trait-obj-different-regions-id-trait.next.stderr
new file mode 100644
index 0000000000000..5a5b4bfcacf43
--- /dev/null
+++ b/tests/ui/cast/ptr-to-trait-obj-different-regions-id-trait.next.stderr
@@ -0,0 +1,15 @@
+error: lifetime may not live long enough
+  --> $DIR/ptr-to-trait-obj-different-regions-id-trait.rs:24:17
+   |
+LL | fn m<'a>() {
+   |      -- lifetime `'a` defined here
+LL |     let unsend: *const dyn Cat<'a> = &();
+LL |     let _send = unsend as *const S<dyn Cat<'static>>;
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type annotation requires that `'a` must outlive `'static`
+   |
+   = note: requirement occurs because of the type `S<dyn Cat<'_>>`, which makes the generic argument `dyn Cat<'_>` invariant
+   = note: the struct `S<T>` is invariant over the parameter `T`
+   = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/cast/ptr-to-trait-obj-different-regions-id-trait.rs b/tests/ui/cast/ptr-to-trait-obj-different-regions-id-trait.rs
index cdd55e243927c..f968dca4fd310 100644
--- a/tests/ui/cast/ptr-to-trait-obj-different-regions-id-trait.rs
+++ b/tests/ui/cast/ptr-to-trait-obj-different-regions-id-trait.rs
@@ -1,3 +1,6 @@
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] compile-flags: -Znext-solver
 //@ check-fail
 //
 // Make sure we can't trick the compiler by using a projection.
diff --git a/tests/ui/coroutine/gen_block.none.stderr b/tests/ui/coroutine/gen_block.none.stderr
index 64fa2be003de5..15123a49e4855 100644
--- a/tests/ui/coroutine/gen_block.none.stderr
+++ b/tests/ui/coroutine/gen_block.none.stderr
@@ -73,7 +73,6 @@ LL |     let _ = || yield true;
    = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information
    = help: add `#![feature(coroutines)]` to the crate attributes to enable
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error: `yield` can only be used in `#[coroutine]` closures, or `gen` blocks
   --> $DIR/gen_block.rs:16:16
@@ -95,7 +94,6 @@ LL |     let _ = #[coroutine] || yield true;
    = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information
    = help: add `#![feature(coroutines)]` to the crate attributes to enable
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error: aborting due to 11 previous errors
 
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/do_not_apply_attribute_without_feature_flag.rs b/tests/ui/diagnostic_namespace/do_not_recommend/do_not_apply_attribute_without_feature_flag.rs
new file mode 100644
index 0000000000000..5548fa2f52e17
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/do_not_apply_attribute_without_feature_flag.rs
@@ -0,0 +1,21 @@
+#![allow(unknown_or_malformed_diagnostic_attributes)]
+
+trait Foo {}
+
+#[diagnostic::do_not_recommend]
+impl<A> Foo for (A,) {}
+
+#[diagnostic::do_not_recommend]
+impl<A, B> Foo for (A, B) {}
+
+#[diagnostic::do_not_recommend]
+impl<A, B, C> Foo for (A, B, C) {}
+
+impl Foo for i32 {}
+
+fn check(a: impl Foo) {}
+
+fn main() {
+    check(());
+    //~^ ERROR the trait bound `(): Foo` is not satisfied
+}
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/do_not_apply_attribute_without_feature_flag.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/do_not_apply_attribute_without_feature_flag.stderr
new file mode 100644
index 0000000000000..e56af28f3fb5d
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/do_not_apply_attribute_without_feature_flag.stderr
@@ -0,0 +1,21 @@
+error[E0277]: the trait bound `(): Foo` is not satisfied
+  --> $DIR/do_not_apply_attribute_without_feature_flag.rs:19:11
+   |
+LL |     check(());
+   |     ----- ^^ the trait `Foo` is not implemented for `()`
+   |     |
+   |     required by a bound introduced by this call
+   |
+   = help: the following other types implement trait `Foo`:
+             (A, B)
+             (A, B, C)
+             (A,)
+note: required by a bound in `check`
+  --> $DIR/do_not_apply_attribute_without_feature_flag.rs:16:18
+   |
+LL | fn check(a: impl Foo) {}
+   |                  ^^^ required by this bound in `check`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/feature-gates/feature-gate-coroutines.none.stderr b/tests/ui/feature-gates/feature-gate-coroutines.none.stderr
index 65e7737ef84d5..032d7adf77ab8 100644
--- a/tests/ui/feature-gates/feature-gate-coroutines.none.stderr
+++ b/tests/ui/feature-gates/feature-gate-coroutines.none.stderr
@@ -47,7 +47,6 @@ LL |     yield true;
    = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information
    = help: add `#![feature(coroutines)]` to the crate attributes to enable
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error: `yield` can only be used in `#[coroutine]` closures, or `gen` blocks
   --> $DIR/feature-gate-coroutines.rs:5:5
@@ -69,7 +68,6 @@ LL |     let _ = || yield true;
    = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information
    = help: add `#![feature(coroutines)]` to the crate attributes to enable
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error: `yield` can only be used in `#[coroutine]` closures, or `gen` blocks
   --> $DIR/feature-gate-coroutines.rs:10:16