I don't know if there is another problem, but this change fixes all
problems in the test case. The fuzzer will eventually tell us if there
is another problem.

R=clemensh@chromium.org

Bug: chromium:1000503
Change-Id: I2f3ca9132e1b9e3f01e9b32604fb39b2272723f1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1784278
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63547}