The creator of the allocator retains ownership and is responsible
for its eventual destruction.

Change-Id: Iaf1b24bee7153b3b1a75df99974adff42c6a197f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1835545
Auto-Submit: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64084}