The tests rely too much on OS state (thread allocation) to be
predictable.

Change-Id: I9a562369a3c72522630a23ee47e3e819b9411c65
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1725626
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ben Titzer <titzer@chromium.org>
Commit-Queue: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62987}