Original design doc:
https://docs.google.com/document/d/1dthXsVHMc1Sd_oYf9a-KZSFOd_a8dUgnt4REAG8YIXA

Design changes:
https://docs.google.com/document/d/1aeEGDm1XSqoJkQQKz9F75WqnuAa2caktxGy_O_KpO9Y

Previous (reverted) version:  https://chromium-review.googlesource.com/c/v8/v8/+/2202981

Relanding with fix: tests need --noincremental-marking

TBR=ishell@chromium.org, ulan@chromium.org, syg@chromium.org, ahaas@chromium.org

Bug: v8:10239
Change-Id: Id122225d5d2ed67cbeb3269df115c7208a33a281
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2306791Reviewed-by: Marja Hölttä <marja@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68929}