Cautiously turn on this flag by default to check the impact on
performance bots. Could show minor regressions in old space and/or
code_and_metadata memory buckets.

Bug: v8:7983
Change-Id: Ic4369cdb0231f4f88eada699da948e8bb48a25fd
Reviewed-on: https://chromium-review.googlesource.com/1162234
Commit-Queue: Yang Guo <yangguo@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54908}