This is identical to these CLs we did to Chromium's mb.py

* https://crrev.com/c/2105272
* https://crrev.com/c/2094482

Bug: chromium:1059167
Change-Id: Ibad4ed0d0655b8bf56a0e7fd672983eac5ac5d38
Reviewers: dpranke@chromium.org, tikuta@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2100697Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66828}