bpo-43268: Pass interp rather than tstate to internal functions (GH-24580)

Pass the current interpreter (interp) rather than the current Python
thread state (tstate) to internal functions which only use the
interpreter.

Modified functions:

* _PyXXX_Fini() and _PyXXX_ClearFreeList() functions
* _PyEval_SignalAsyncExc(), make_pending_calls()
* _PySys_GetObject(), sys_set_object(), sys_set_object_id(), sys_set_object_str()
* should_audit(), set_flags_from_config(), make_flags()
* _PyAtExit_Call()
* init_stdio_encoding()
* etc.
diff --git a/Python/ceval_gil.h b/Python/ceval_gil.h
index 56944b8..9b8b432 100644
--- a/Python/ceval_gil.h
+++ b/Python/ceval_gil.h
@@ -318,7 +318,7 @@ take_gil(PyThreadState *tstate)
 
     /* Don't access tstate if the thread must exit */
     if (tstate->async_exc != NULL) {
-        _PyEval_SignalAsyncExc(tstate);
+        _PyEval_SignalAsyncExc(tstate->interp);
     }
 
     MUTEX_UNLOCK(gil->mutex);