Objects in the from page could be promoted into the shared heap as
well. While this shouldn't happen for references into evacuation
candidates, I think it's easier to understand when there is a single
conditional branch at the end.

Bug: v8:13227, v8:11708
Change-Id: I999f10228ed5fdd70675a6d9c1e178eb152f39f0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3854502Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82694}