We must ensure that the sweeper is not running or has already swept
mutable_double_buffer. Otherwise the GC can add it to the free list.

Bug: v8:11837
Change-Id: Ifd9cf15f1c94f664fd6489c70bb38b59730cdd78
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2928181
Commit-Queue: Victor Gomes <victorgomes@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74859}