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/iterobject.c b/Objects/iterobject.c
index 95ee56d..174bd98 100644
--- a/Objects/iterobject.c
+++ b/Objects/iterobject.c
@@ -103,7 +103,7 @@
 	0,					/* tp_print */
 	0,					/* tp_getattr */
 	0,					/* tp_setattr */
-	0,					/* tp_compare */
+	0,					/* tp_reserved */
 	0,					/* tp_repr */
 	0,					/* tp_as_number */
 	0,					/* tp_as_sequence */
@@ -207,7 +207,7 @@
 	0,					/* tp_print */
 	0,					/* tp_getattr */
 	0,					/* tp_setattr */
-	0,					/* tp_compare */
+	0,					/* tp_reserved */
 	0,					/* tp_repr */
 	0,					/* tp_as_number */
 	0,					/* tp_as_sequence */