15b4758745
Adds Auxiliary* nodes to support extending the AST from outside package:kernel TEST=existing Change-Id: I350718a1b02c188f212b3390050b60484f9f4b3b Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/326305 Reviewed-by: Ömer Ağacan <omersa@google.com> Commit-Queue: Johnni Winther <johnniwinther@google.com> Reviewed-by: Jens Johansen <jensj@google.com> Reviewed-by: Mayank Patke <fishythefish@google.com>