Performance and stability improvements on all platforms.

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

Change-Id: I11f4bfada976929f5b6554d58d2c0c048f451a6d
Reviewed-on: https://chromium-review.googlesource.com/c/1495901
Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/7.4.258@{#1}
Cr-Branched-From: b8c79ff6e095e5820a8b6707e9a8e83b074824bd-refs/heads/master@{#59957}