Currently, the target of a use statement will be updated with
the visibility of the use statement itself (if the use statement was
visible).

This commit ensures that if the path to the target item is via another
use statement then that intermediate use statement will also have the
visibility updated like the target. This silences incorrect
`unreachable_pub` lints with inactionable suggestions.

…alexcrichton

Print a slightly clearer message when failing to launch a thread

As discussed in rust-lang#46345, the `io::Error` you get when a thread fails to launch is of type `io::ErrorKind::WouldBlock`. This is super uninformative when an arbitrary `thread::spawn` fails somewhere in your code:

```
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Os { code: 11,
kind: WouldBlock, message: "operation would block" }', src/libcore/result.rs:997:5
```

This PR improves the situation a little bit by using `expect` instead of `unwrap`. I don't consider this a complete fix for rust-lang#46345 though.

…ietMisdreavus

Fix invalid background color

As discussed in rust-lang#57814.

r? @QuietMisdreavus

add typo suggestion to unknown attribute error

Provides a suggestion using Levenshtein distance to suggest built-in attributes and attribute macros.

Fixes rust-lang#49270.

Pretty print `$crate` as `crate` or `crate_name` in more cases

So, people do parse output of `--pretty=expanded` (sigh), so covering only the legacy proc-macro case (like it was done in rust-lang#57155) is not enough.

This PRs resolves all `$crate`s produced by macros, so they are all printed in the parseable form `$crate::foo` -> `crate::foo` or `crate_name::foo`.

Fixes rust-lang#38016 (comment)
Fixes rust-lang#57155 (comment)

Update visibility of intermediate use items.

Fixes rust-lang#57410 and fixes rust-lang#53925 and fixes rust-lang#47816.

Currently, the target of a use statement will be updated with
the visibility of the use statement itself (if the use statement was
visible).

This PR ensures that if the path to the target item is via another
use statement then that intermediate use statement will also have the
visibility updated like the target. This silences incorrect
`unreachable_pub` lints with inactionable suggestions.