The first GC will collect dead JSArrayBuffers, but the release of the
underlying JSArrayBuffer::Allocations might be delayed. Hence, a second
GC might be needed.

R=ulan@chromium.org

Bug: v8:7621
Change-Id: Iee714f05cb939bb084d064be6d31dfbab32ff4ba
Reviewed-on: https://chromium-review.googlesource.com/995533
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52357}