The async state machine uses a single state in the heap to store the current exception and stacktrace when within a catch block in case they need to be rethrown. When catch blocks are nested this state can be overwritten.
With this new change, before entering a new catch we store the current value of the exception/stacktrace in a local that we can restore after exiting the associated catch blocks. A wasm catch can represent multiple Dart catch blocks so we only need to store the state per wasm catch.
Fixes: https://github.com/dart-lang/sdk/issues/59981
Change-Id: I738084fdecdf5aceac65c5d3698e40b791175171
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/405920
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Nate Biggs <natebiggs@google.com>
Nate Biggs
b969f32a76