Performance and stability improvements on all platforms.

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

Change-Id: I418ac91697b7db000d86b55938c301f4ebd44198
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1590162
Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/7.6.73@{#1}
Cr-Branched-From: 7d6f2052091dad8f0a26c6b8b2c883c29c32298b-refs/heads/master@{#61127}