Experiment with enabling FLAG_local_heaps for a few days to see whether
pause times regress and to catch bugs.

Bug: v8:10315
Change-Id: Iefc329bbc1b8131796f1db2a729ee358bef88894
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2375190Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69561}