9b67562b4d
Automatic set coverage when loading snapshot TEST=Existing tests, manual inspection of reduction in sdk snapshot sizes (see data in comments in https://dart-review.googlesource.com/c/sdk/+/370501) Change-Id: I044616144c2defeed252a6715eba1abcabffc86d Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/371700 Reviewed-by: Slava Egorov <vegorov@google.com> Commit-Queue: Jens Johansen <jensj@google.com>