Just a minor fix to skip the third GC after which we fail anyway.

R=ulan@chromium.org

Bug: v8:7621
Change-Id: I4dd6bcedc20ecb75dc06af02649ff5c7b67317d0
Reviewed-on: https://chromium-review.googlesource.com/1224434Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55870}