This was supposed to be only a clean-up, but the original code even
invalidated a test and thereby covered a test. I fixed the bug here as
well.

Without testing it I think this fixes https://crbug.com/964607.

Bug: v8:9183
Change-Id: I076f40a2302bfd5b7cecd2ae35d4e05a465e054b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1621935
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61691}