Port SetAttrString/HasAttrString to SetAttrId/GetAttrId.
diff --git a/Objects/descrobject.c b/Objects/descrobject.c
index 6e2d34e..b328a45 100644
--- a/Objects/descrobject.c
+++ b/Objects/descrobject.c
@@ -1311,7 +1311,7 @@
                 in dict of the subclass instance instead,
                 otherwise it gets shadowed by __doc__ in the
                 class's dict. */
-                int err = PyObject_SetAttrString(self, "__doc__", get_doc);
+                int err = _PyObject_SetAttrId(self, &PyId___doc__, get_doc);
                 Py_DECREF(get_doc);
                 if (err < 0)
                     return -1;