Eric Snow's implementation of PEP 421.

Issue 14673: Add sys.implementation
diff --git a/Objects/object.c b/Objects/object.c
index 20eaf31..1211cc3 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -1707,6 +1707,9 @@
 
     if (PyType_Ready(&PyZip_Type) < 0)
         Py_FatalError("Can't initialize zip type");
+
+    if (PyType_Ready(&_PyNamespace_Type) < 0)
+        Py_FatalError("Can't initialize namespace type");
 }