bpo-35370: Add _PyEval_SetTrace() function (GH-18975)

* sys.settrace(), sys.setprofile() and _lsprof.Profiler.enable() now
  properly report PySys_Audit() error if "sys.setprofile" or
  "sys.settrace" audit event is denied.
* Add _PyEval_SetProfile() and _PyEval_SetTrace() function: similar
  to PyEval_SetProfile() and PyEval_SetTrace() but take a tstate
  parameter and return -1 on error.
* Add _PyObject_FastCallTstate() function.