Auto merge of #114591 - joboet:thread_parking_ordering_fix, r=thomcc

Synchronize with all calls to `unpark` in id-based thread parker

[The documentation for `thread::park`](https://doc.rust-lang.org/nightly/std/thread/fn.park.html#memory-ordering) guarantees that "park synchronizes-with all prior unpark operations". In the id-based thread parking implementation, this is not implemented correctly, as the state variable is reset with a simple store, so there will not be a *synchronizes-with* edge if an `unpark` happens just before the reset. This PR corrects this, replacing the load-check-reset sequence with a single `compare_exchange`.

Author: bors