Performance and stability improvements on all platforms.

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

Change-Id: I0abe3222e1768b1da98faa605b3961c3904411ca
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1614939
Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/7.6.195@{#1}
Cr-Branched-From: 48b414715ee0e3985fdb1f63d9b178571f9c80b9-refs/heads/master@{#61561}