This CL adds a moving GC-safe, JS-exposed mutex behind the
--harmony-struct flag. It uses a ParkingLot-inspired algorithm and
each mutex manages its own waiter queue.

For more details, please see the design doc: https://docs.google.com/document/d/1QHkmiTF770GKxtoP-VQ1eKF42MpedLUeqiQPfCqus0Y/edit?usp=sharing

Bug: v8:12547
Cq-Include-Trybots: luci.v8.try:v8_linux64_tsan_rel_ng
Change-Id: Ic58f8750d2e14ecd573173d17d5235a136bedef9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3595460
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80789}