Performance and stability improvements on all platforms.

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

Change-Id: I1b1a8e322fcda8449e189c1258d22c82666f30d2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1590657
Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/7.6.76@{#1}
Cr-Branched-From: ff14c88679aac320840109717dd79f9bd5559722-refs/heads/master@{#61137}