Complete implementation of Heap::MakeHeapIterable() by also making the
LABs of paged spaces iterable. This method is the one to use when
the heap and/or a particular space shall be iterable.

Bug: v8:12338
Change-Id: Id859cf1a05df21a54939c504c59d7b1ccd659c9b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3277888Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77891}