bpo-37483: add _PyObject_CallOneArg() function (#14558)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 85134c7..92f97e6 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -736,8 +736,7 @@
         _Py_IDENTIFIER(__getattr__);
         getattr = _PyDict_GetItemId(m->md_dict, &PyId___getattr__);
         if (getattr) {
-            PyObject* stack[1] = {name};
-            return _PyObject_FastCall(getattr, stack, 1);
+            return _PyObject_CallOneArg(getattr, name);
         }
         _Py_IDENTIFIER(__name__);
         mod_name = _PyDict_GetItemId(m->md_dict, &PyId___name__);