- implemented as a single-linked list with head and tail
  pointers. The tail pointer is needed for freelist appending;
- stores entries in buckets, where bucket[log2(size)] stores
  entries >= size;
- implements worst fit allocation to amortize free list call;
- ported from Blink: https://bit.ly/2yC8XKJ.

Bug: chromium:1056170
Change-Id: I26cf62c948c95a7cbfecd5f7f22ad975e6b8c732
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2157376
Commit-Queue: Anton Bikineev <bikineev@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67310}