Performance and stability improvements on all platforms.

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

Change-Id: I7cafa8760542c17ba157f96bfef786328edd3fba
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1593096
Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/7.6.83@{#1}
Cr-Branched-From: 7584a9b02c5cd8aac004d3b2dee8c2d96a204fa1-refs/heads/master@{#61145}