Report UNUSED_LABEL when null safety, fix for crash.

Bug: https://github.com/dart-lang/sdk/issues/42077
Change-Id: I85325ae1f2d25f680182d07ef50ddb56633b89f3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/149240
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>

https://dart.googlesource.com/sdk/+/860d3c0697e2bff140a0d956a8d1ccd46348d13e
1 file changed
tree: b623a215d2cc37eb9c6bd8fd00c5cdafc3f27627
  1. commits.json