Performance and stability improvements on all platforms.

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

Change-Id: I9789806e69ed72f66186f4c38cb67096ab79d865
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622025
Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/7.6.230@{#1}
Cr-Branched-From: be014256adea1552d4a044ef80616cdab6a7d549-refs/heads/master@{#61676}