bpo-43977: Use tp_flags for collection matching (GH-25723)
* Add Py_TPFLAGS_SEQUENCE and Py_TPFLAGS_MAPPING, add to all relevant standard builtin classes.
* Set relevant flags on collections.abc.Sequence and Mapping.
* Use flags in MATCH_SEQUENCE and MATCH_MAPPING opcodes.
* Inherit Py_TPFLAGS_SEQUENCE and Py_TPFLAGS_MAPPING.
* Add NEWS
* Remove interpreter-state map_abc and seq_abc fields.
diff --git a/Objects/descrobject.c b/Objects/descrobject.c
index dd41620..57a9607 100644
--- a/Objects/descrobject.c
+++ b/Objects/descrobject.c
@@ -1852,7 +1852,8 @@ PyTypeObject PyDictProxy_Type = {
PyObject_GenericGetAttr, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
- Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC, /* tp_flags */
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
+ Py_TPFLAGS_MAPPING, /* tp_flags */
0, /* tp_doc */
mappingproxy_traverse, /* tp_traverse */
0, /* tp_clear */