6f54f6236e
Add AwaitExpression.runtimeTypeCheck to support easy backend implementation of runtime type check. In response to https://github.com/dart-lang/sdk/issues/49396 TEST=pkg/front_end/testcases/general/issue49396.dart Change-Id: I13b9b14566ebc34cdb0811c16a262421417b68e7 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/270723 Commit-Queue: Johnni Winther <johnniwinther@google.com> Reviewed-by: Martin Kustermann <kustermann@google.com> Reviewed-by: Chloe Stefantsova <cstefantsova@google.com>