Backed out changeset b9c9691c72c5

Issue #28858: The change b9c9691c72c5 introduced a regression. It seems like
_PyObject_CallArg1() uses more stack memory than
PyObject_CallFunctionObjArgs().
diff --git a/Modules/_struct.c b/Modules/_struct.c
index 4ef5c89..1d7a935 100644
--- a/Modules/_struct.c
+++ b/Modules/_struct.c
@@ -2046,7 +2046,7 @@
         return s_object;
     }
 
-    s_object = _PyObject_CallArg1((PyObject *)(&PyStructType), fmt);
+    s_object = PyObject_CallFunctionObjArgs((PyObject *)(&PyStructType), fmt, NULL);
     if (s_object != NULL) {
         if (PyDict_Size(cache) >= MAXCACHE)
             PyDict_Clear(cache);