Rename _PyObject_FastCall() to _PyObject_FastCallDict()

Issue #27809:

* Rename _PyObject_FastCall() function to _PyObject_FastCallDict()
* Add _PyObject_FastCall(), _PyObject_CallNoArg() and _PyObject_CallArg1()
  macros calling _PyObject_FastCallDict()

Objects/iterobject.c

@@ -214,7 +214,7 @@ calliter_iternext(calliterobject *it)
         return NULL;
     }
 
-    result = _PyObject_FastCall(it->it_callable, NULL, 0, NULL);
+    result = _PyObject_CallNoArg(it->it_callable);
     if (result != NULL) {
         int ok;