It is not allowed to invoke ResetPendingObject() in
MarkCompactCollector::StartMarking(). This method is invoked when
starting incremental marking, at this point the object might not be
initialized.

Bug: v8:10315
Change-Id: I7659855d78fbb28536f57b26e8a7d33c1ba4092e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2424267Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70059}