Performance and stability improvements on all platforms.

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

Change-Id: Iccba950bcd2d28ff0c6c0908bf0f5bca5c38eb7a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1619149
Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/7.6.211@{#1}
Cr-Branched-From: 90b39673c398d91e5dfa985b639cb4feb9f8df05-refs/heads/master@{#61632}