Reapply "Synchronize Virtual Threads"

This reland fixed the cpplint errors shown in
http://b/487668811

A thin lock id is allocated for every virtual thread.

If a virtual thread owns a thin lock, and is mounted on a platform thread,
the platform thread needs to be suspended for lock inflation.

During lock inflation, we make sure that the virtual thread stays
unmounted or mounted on a platform thread.

Flag: com.android.art.flags.virtual_thread_impl_v1
Bug: 454244174
Test: testrunner.py
Change-Id: I6bed4dd52572e898fc9d857f1ca645468e13ae7b