Performance and stability improvements on all platforms.

TBR=v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com

Change-Id: I70ca5b9fafe3570c100ab5c43f9ebef2ea731acc
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1645494
Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/7.7.19@{#1}
Cr-Branched-From: fe9d6a49d18e79bb906df14093672bc988cf76f1-refs/heads/master@{#61992}