Performance and stability improvements on all platforms.

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

Change-Id: I870bdcc25da8ed8e6c82e903b5d18f5ef32f99a4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1557347
Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/7.5.216@{#1}
Cr-Branched-From: f7f24659c38d009803e1f9f6ce57dd88d13029dc-refs/heads/master@{#60678}