82420ba66c
All work on https://github.com/dart-lang/language/issues/3100 (Change flow analysis to assume sound null safety once unsound null safety support is fully removed) will be guarded by this flag. Bug: https://github.com/dart-lang/language/issues/3100 Change-Id: I0a6e7b732520ed70944141b4bb02832b7d0d969b Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/417906 Reviewed-by: Kevin Moore <kevmoo@google.com> Reviewed-by: Konstantin Shcheglov <scheglov@google.com> Commit-Queue: Paul Berry <paulberry@google.com>