This also removes unused free list classes.

Change-Id: I705ca3aca94e404cf388e6c9bac2ff9f3c38fe10
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2241525
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68322}