Upon Scavenge, nodes may generally be reclaimed or updated. This logic
did not consider the fact that objects may be Smis and thus should be
ignored.

Bug: v8:1341111
Change-Id: I62f68e673377a895d3487ec9d372001342e77e8a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3740722Reviewed-by: Omer Katz <omerkatz@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81492}