Performance and stability improvements on all platforms.

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

Change-Id: I2ceeb01127b57db09108e0fcb2d2ad1563dd0fbc
Reviewed-on: https://chromium-review.googlesource.com/c/1368344
Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/7.3.67@{#1}
Cr-Branched-From: 9efb53db207eaebba13b5eb1af266695132d10ec-refs/heads/master@{#58102}