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/cellobject.c b/Objects/cellobject.c
index c2194b7..d7908de 100644
--- a/Objects/cellobject.c
+++ b/Objects/cellobject.c
@@ -154,7 +154,7 @@
 	0,                                      /* tp_print */
 	0,	                                /* tp_getattr */
 	0,					/* tp_setattr */
-	0,					/* tp_compare */
+	0,					/* tp_reserved */
 	(reprfunc)cell_repr,			/* tp_repr */
 	0,					/* tp_as_number */
 	0,			                /* tp_as_sequence */