Add comment to assertion

Author: encukou

Objects/moduleobject.c

@@ -29,6 +29,10 @@ static PyMemberDef module_members[] = {
 
 static void
 assert_def_missing_or_redundant(PyModuleObject *m) {
+    /* We copy all relevant info into the module object.
+     * Modules created using a def keep a reference to that (statically
+     * allocated) def; the info there should match what we have in the module.
+     */
 #ifdef Py_DEBUG
     if (m->md_token_is_def) {
         PyModuleDef *def = (PyModuleDef *)m->md_token;