This CL fixes a spec violation that new spec tests uncovered.

R=thibaudm@chromium.org
CC=ecmziegler@chromium.org

Change-Id: I1004eca9e4f98a0960795907fea0ab263c907938
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2122022Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66874}