With --verify-heap verify all client heaps before and after a shared
GC. This ensures that the OLD_TO_SHARED remembered set is properly
filled for each client isolate.

Bug: v8:11708
Change-Id: I1506a419c7a91c5baa87ce251da9861d8ad9e066
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3857559Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82829}