Performance and stability improvements on all platforms.

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

Change-Id: I3ebf906553a98ac9f33bfab6ff06a1059de10ce2
Reviewed-on: https://chromium-review.googlesource.com/c/1477372
Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/7.4.195@{#1}
Cr-Branched-From: 4d9381baa6b44b3188e4581041c364fcc90dd09f-refs/heads/master@{#59666}