bpo-42128: Structural Pattern Matching (PEP 634) (GH-22917)

Co-authored-by: Guido van Rossum <guido@python.org>
Co-authored-by: Talin <viridia@gmail.com>
Co-authored-by: Pablo Galindo <pablogsal@gmail.com>
diff --git a/Objects/longobject.c b/Objects/longobject.c
index 02b3603..d5037a7 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -5639,7 +5639,8 @@ PyTypeObject PyLong_Type = {
     0,                                          /* tp_setattro */
     0,                                          /* tp_as_buffer */
     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE |
-        Py_TPFLAGS_LONG_SUBCLASS,               /* tp_flags */
+        Py_TPFLAGS_LONG_SUBCLASS |
+        _Py_TPFLAGS_MATCH_SELF,               /* tp_flags */
     long_doc,                                   /* tp_doc */
     0,                                          /* tp_traverse */
     0,                                          /* tp_clear */