Performance and stability improvements on all platforms.

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

Change-Id: I58660df7be358b6bd2d0827c4b688aaaa7231af9
Reviewed-on: https://chromium-review.googlesource.com/c/1488892
Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/7.4.222@{#1}
Cr-Branched-From: 0686bf7ba34780ddeb8c2a7288c960b140447563-refs/heads/master@{#59862}