The new micro-benchmark measures performance of returning 2 values
via list, dedicated class, record and a record with named fields.
Requires '--enable-experiment=records' flag to run.
Issue: https://github.com/dart-lang/sdk/issues/49719
Change-Id: I895d955efb2fc4f1c04b31b113cd8e01db47132a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/265121
Reviewed-by: Slava Egorov <vegorov@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
