Bug: https://github.com/dart-lang/sdk/issues/52689 Change-Id: I54be397cfbf8519fe5b5a51b793fe46d602124d9 Fixes: https://github.com/dart-lang/sdk/issues/52689 Bug: https://github.com/dart-lang/sdk/issues/53096 TEST=isolate_local_function_callbacks_test.dart, plus generated tests and additions to existing tests CoreLibraryReviewExempt: The isolate and FFI packages are VM-only Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/317060 Commit-Queue: Liam Appelbe <liama@google.com> Reviewed-by: Liam Appelbe <liama@google.com> Reviewed-by: Martin Kustermann <kustermann@google.com> Reviewed-by: Daco Harkes <dacoharkes@google.com>