Issue #1717: rename tp_compare to tp_reserved.  I'll change the
type of tp_compare in a separate commit, for ease of reversion
should things go wrong.
diff --git a/Objects/codeobject.c b/Objects/codeobject.c
index 01a637a..65868e4 100644
--- a/Objects/codeobject.c
+++ b/Objects/codeobject.c
@@ -399,7 +399,7 @@
 	0,				/* tp_print */
 	0, 				/* tp_getattr */
 	0,				/* tp_setattr */
-	0,		 		/* tp_compare */
+	0,		 		/* tp_reserved */
 	(reprfunc)code_repr,		/* tp_repr */
 	0,				/* tp_as_number */
 	0,				/* tp_as_sequence */