AST for RecordTypeAnnotation.
AST for RecordTypeAnnotation.

Change-Id: I3d52c97fe4f01cfb06923829e6e519d1990ae62b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/254120
Reviewed-by: Samuel Rawlins <5cf2cac5eec2ad6d0eb2b0f4ff6af9a590ce2bf6@google.com>
Reviewed-by: Brian Wilkerson <1f7641b6b14c52b9163524ab8d9aabff80176f21@google.com>
Commit-Queue: Konstantin Shcheglov <09e4d7516628963212bf4aace2f97603d2b706e4@google.com>

dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk