Asserts if a TextPainter gets disposed more than once (#145124)

The overflow indicator was sharing the same `TextPainter`.

packages/flutter/lib/src/painting/text_painter.dart

@@ -1659,6 +1659,7 @@ class TextPainter {
   ///
   /// After disposal this painter is unusable.
   void dispose() {
+    assert(!debugDisposed);
     assert(() {
       _disposed = true;
       return true;

packages/flutter/lib/src/rendering/debug_overflow_indicator.dart

@@ -109,9 +109,10 @@ mixin DebugOverflowIndicatorMixin on RenderObject {
     );
   static final Paint _labelBackgroundPaint = Paint()..color = const Color(0xFFFFFFFF);
 
-  final List<TextPainter> _indicatorLabel = List<TextPainter>.filled(
+  final List<TextPainter> _indicatorLabel = List<TextPainter>.generate(
     _OverflowSide.values.length,
-    TextPainter(textDirection: TextDirection.ltr), // This label is in English.
+    (int i) => TextPainter(textDirection: TextDirection.ltr), // This label is in English.
+    growable: false,
   );
 
   @override

packages/flutter/test/painting/text_painter_test.dart

@@ -1429,6 +1429,12 @@ void main() {
     expect(painter.debugDisposed, true);
   });
 
+  test('TextPainter - asserts if disposed more than once', () {
+    final TextPainter painter = TextPainter()..dispose();
+    expect(painter.debugDisposed, isTrue);
+    expect(painter.dispose, throwsAssertionError);
+  });
+
   test('TextPainter computeWidth', () {
     const InlineSpan text = TextSpan(text: 'foobar');
     final TextPainter painter = TextPainter(text: text, textDirection: TextDirection.ltr);