Before this CL array buffer counters were only decremented at the next
GC. This CL makes freed_bytes_ an atomic variable which is incremented
by the concurrent sweeping task. The main thread now also inspects this
value when adding new JSArrayBuffers to update counters sooner.

Bug: v8:10064
Change-Id: Ibcb245b541e806b95a3c2c42d3cc3affe7739e4d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2047043
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66221}