This allocator was only required to ensure zero-initialization of pages
returned by the BoundedPageAllocator. With crrev/c/3208812, this is now
possible in a (hopefully) more efficient way by using the
kAllocatedPagesMustBeZeroInitialized PageInitializationMode.

Bug: chromium:1218005
Change-Id: I504248107a54c90285aa9a3a616b334aaa3fcb7a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3211583Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Samuel Groß <saelo@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77298}