The host object may have an impossible markbit pattern if it is a
one-word filler followed by an already marked object.

Bug: v8:10698
Change-Id: I498e6f0768fbdb181fc893f98f224dd3cd0e37e6
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2295600Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68848}