... as the main thread might change its contents.

Bug: v8:12174, v8:7790
Change-Id: I66b2cafc7ddc9b387223693595a9d810b272d7b9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3141586Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/main@{#76685}