Performance and stability improvements on all platforms.

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

Change-Id: I6db74ae8bedfef7c45ffa845132012f20280a584
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1589335
Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/7.6.67@{#1}
Cr-Branched-From: 0875682600077e5699ade7a68b6c1e89996682d4-refs/heads/master@{#61102}