[parser] Parse a!?[0]

Fixes #41177.

Change-Id: I135f0b7aedbcb320ab0d1a1806b2ad3bedcda307
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/141886
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Commit-Queue: Jens Johansen <jensj@google.com>

https://dart.googlesource.com/sdk/+/43079207d4b6e5b7954b29cc43747bd7a6595176
1 file changed
tree: 59a04c1b4556459bd6b2ae565b705795b43d40b8
  1. commits.json