Sets the priority of a specified thread.
PR_SetThreadPriority has the following parameters:
- A valid identifier for the thread whose priority you want to set.
- The priority you want to set.
Modifying the priority of a thread other than the calling thread is risky. It is difficult to ensure that the state of the target thread permits a priority adjustment without ill effects. It is preferable for a thread to specify itself in the thread parameter when it calls