The counter as size_t can legitimately overflow on 32-bit systems, since
decreasing the counters is performed after all backing stores were
freed on a background thread. Before sweeping is finished a new backing
store could already be allocated which then leads to the overflow.

Bug: v8:11788, chromium:1211437
Change-Id: Id9f3e58b0e84e831fe47109f7deb3a05ae7e489c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2922242
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74836}