617d0a8e96
This is a preparation for removing the subtype checking procedure that ignores the nullability in the input types. Change-Id: I3c1db55abde0433e9059d949f1c98aaeb61e210c Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/428980 Commit-Queue: Chloe Stefantsova <cstefantsova@google.com> Reviewed-by: Erik Ernst <eernst@google.com> Reviewed-by: Johnni Winther <johnniwinther@google.com>