Weak containers are retraced if they are found through the stack using
the conservative scanner, possibly resulting in a race with the
concurrent marker.

Bug: v8:12648
Change-Id: I0936a2953e3e2151cea4191f335a091b0e334e6b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3474678
Auto-Submit: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79184}