Manual engine roll to b2640d97e7e8034f28b4e7b92c15b0824e433897 (#45000)

Fixes failures in some tests which used regular expressions to compare
stack traces which had instances of "<asynchronous suspension>".

bin/internal/engine.version

-096ba6892a435a9149b0406592eab7ba866bceb8
+b2640d97e7e8034f28b4e7b92c15b0824e433897

packages/flutter/test/foundation/error_reporting_test.dart

@@ -79,7 +79,6 @@ Future<void> main() async {
       'When the exception was thrown, this was the stack:\n'
       '#0      getSampleStack\\.<anonymous closure> \\([^)]+flutter/test/foundation/error_reporting_test\\.dart:[0-9]+:[0-9]+\\)\n'
       '#2      getSampleStack \\([^)]+flutter/test/foundation/error_reporting_test\\.dart:[0-9]+:[0-9]+\\)\n'
-      '<asynchronous suspension>\n' // TODO(ianh): https://github.com/flutter/flutter/issues/4021
       '#3      main \\([^)]+flutter/test/foundation/error_reporting_test\\.dart:[0-9]+:[0-9]+\\)\n'
       '(.+\n)+' // TODO(ianh): when fixing #4021, also filter out frames from the test infrastructure below the first call to our main()
       '\\(elided [0-9]+ frames from package dart:async\\)\n'
@@ -162,7 +161,6 @@ Future<void> main() async {
       'When the exception was thrown, this was the stack:\n'
       '#0      getSampleStack\\.<anonymous closure> \\([^)]+flutter/test/foundation/error_reporting_test\\.dart:[0-9]+:[0-9]+\\)\n'
       '#2      getSampleStack \\([^)]+flutter/test/foundation/error_reporting_test\\.dart:[0-9]+:[0-9]+\\)\n'
-      '<asynchronous suspension>\n' // TODO(ianh): https://github.com/flutter/flutter/issues/4021
       '#3      main \\([^)]+flutter/test/foundation/error_reporting_test\\.dart:[0-9]+:[0-9]+\\)\n'
       '(.+\n)+' // TODO(ianh): when fixing #4021, also filter out frames from the test infrastructure below the first call to our main()
       '\\(elided [0-9]+ frames from package dart:async\\)\n'

packages/flutter/test/foundation/stack_trace_test.dart

@@ -23,7 +23,6 @@ void main() {
     final List<String> filtered = FlutterError.defaultStackFilter(StackTrace.current.toString().trimRight().split('\n')).toList();
     expect(filtered.length, greaterThanOrEqualTo(3));
     expect(filtered[0], matches(r'^#0 +main\.<anonymous closure> \(.*stack_trace_test\.dart:[0-9]+:[0-9]+\)$'));
-    expect(filtered[1], equals('<asynchronous suspension>'));
     expect(filtered.last, matches(r'^\(elided [1-9][0-9]+ frames from package dart:async(, package dart:async-patch,)? and package stack_trace\)$'));
   });
 }