Performance and stability improvements on all platforms.

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

Change-Id: I19ad257b614b9a9b521eea845a4d0e322f4f42e5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1550700
Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/7.5.171@{#1}
Cr-Branched-From: cf81ce239c2b28a08c2b1e2e9c17a1f42ed0bad0-refs/heads/master@{#60592}