This change is needed as a consequence of
https://github.com/dart-lang/language/pull/2422
where `()` was introduced as the syntax for the empty record as well
as the empty record type.
Change-Id: Ia8b3f590361343ca14355043c5898e7bd084c04e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/261645
Reviewed-by: William Hesse <whesse@google.com>
Auto-Submit: Erik Ernst <eernst@google.com>
Commit-Queue: William Hesse <whesse@google.com>
