During verification all LABs are iterable. For PagedNewSpace we can
therefore use the property that all new space pages are iterable.

Bug: v8:12612
Change-Id: I71ec079fde3c0b719ccf91b431b0b29a8a9c5a2e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3888019Reviewed-by: Omer Katz <omerkatz@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/main@{#83126}