Performance and stability improvements on all platforms.

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

Change-Id: I23dea1c741b302d9ceb16552d512e4d33894d6a4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1562588
Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/7.5.245@{#1}
Cr-Branched-From: 450ada04b2ef6371917dcdfad9cfc57e83b08743-refs/heads/master@{#60759}