Performance and stability improvements on all platforms.

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

Change-Id: I2b6dd1414de7b1a760bafca165715af50dcd4bcb
Reviewed-on: https://chromium-review.googlesource.com/c/1493049
Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/7.4.244@{#1}
Cr-Branched-From: 62bdde9242ab98f576f6909d966e4cf1e7070ffa-refs/heads/master@{#59929}