Adds the PersistentHandles class, which serves as a container for
handles that can be passed back and forth between threads. Allocation
and deallocation of this class is thread-safe and the isolate tracks
all PersistentHandles containers.
Design doc: https://docs.google.com/document/d/17yKs-6apE2rGEag7tDsoyeRxg99c1dXyXQ2MfHe65tY/edit?usp=sharing
Bug: v8:10315
Change-Id: I4b9c958c9a57d755ca68862197501f75274670fb
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2128058
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67004}
