R=ahaas@chromium.org

Bug: v8:9429, v8:9396
Change-Id: I2a66142c04b2ec0e3ed57ea2392dda6d17d53b38
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1687895
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62554}