Performance and stability improvements on all platforms.

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

Change-Id: If23fde88acd1a82304e0ea8fea67fcdb0438d8e6
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1550701
Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/7.5.172@{#1}
Cr-Branched-From: fe00be43e43893f25f61c3ab669d31b27b93b63d-refs/heads/master@{#60593}