Performance and stability improvements on all platforms.

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

Change-Id: Id73b7f459f05ff416decf9d415aaac4894f231b2
Reviewed-on: https://chromium-review.googlesource.com/c/1477333
Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/7.4.194@{#1}
Cr-Branched-From: 6e0981af5881d4eab5f7e8d2144048c3e25fc183-refs/heads/master@{#59665}