This is a port of src/components/gc that was added recently.

Differences:
- Added back bucketing to the page pool, as that guarantees that
  arenas used for specific types do not have their pages used by other
  arenas.
- Replaced base::flat_map with std::map. This may cause performance
  regressions when using PageMemoryRegionTree in hot paths. A
  vector-like representation may be used to fix such a regression

This reverts commit a056cea5.

Bug: chromium:1056170
Change-Id: Iffb8b0d91c8cca1815d7a1cda9486e7716aea75f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2144060
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67117}