Issue #18722: Remove uses of the "register" keyword in C code.
diff --git a/Objects/namespaceobject.c b/Objects/namespaceobject.c
index 8c51b07..9e95094 100644
--- a/Objects/namespaceobject.c
+++ b/Objects/namespaceobject.c
@@ -176,7 +176,7 @@
 PyDoc_STRVAR(namespace_reduce__doc__, "Return state information for pickling");
 
 static PyObject *
-namespace_reduce(register _PyNamespaceObject *ns)
+namespace_reduce(_PyNamespaceObject *ns)
 {
     PyObject *result, *args = PyTuple_New(0);