Replace PyObject_CallFunction calls with only object args
with PyObject_CallFunctionObjArgs, which is 30% faster.
diff --git a/Modules/gcmodule.c b/Modules/gcmodule.c
index 6ff2c9a..872727d 100644
--- a/Modules/gcmodule.c
+++ b/Modules/gcmodule.c
@@ -603,7 +603,7 @@
 		assert(callback != NULL);
 
 		/* copy-paste of weakrefobject.c's handle_callback() */
-		temp = PyObject_CallFunction(callback, "O", wr);
+		temp = PyObject_CallFunctionObjArgs(callback, wr, NULL);
 		if (temp == NULL)
 			PyErr_WriteUnraisable(callback);
 		else