When a FinalizerEntry's target gets promoted, the associated external size needs to also get promoted. We were handling the cases where the FinalizerEntry itself was either already old or remained new, but not the case where it was promoted. Failing to promote the external size meant that when the finalizer was collected, external size was subtraced from old space that was still being attributed to new space, so the old space total external size became negative.
TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/50537
Change-Id: Id2fe2d748311de73f04de367c9cd153d87b74ad1
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/272350
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
