[RFC] Frame Scoped Lifetime for In Frame Temperary Refs #3970

Summary

for some mutex or rwlock we can use atomic CAS operations instead if we can garentee the clearup within frame lifetime

Detailed Explanation

For example PyObject hold a PyTypeRef witch is protected by a rwlock, we could replace the lock with a atomic CAS operations
then hold the old PyRef until the current frame is done. Also we need to garentee no reference to be keep across the frames.

Drawbacks, Rationale, and Alternatives

Unresolved Questions

should we use rust lifetime system or just the coding rules to make the garrentee?
where should the lifetime placed? with VirtualMachine or the struct wrap the VirtualMachine or seperate parameter?