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/structseq.c b/Objects/structseq.c
index 808f938..54c8deb 100644
--- a/Objects/structseq.c
+++ b/Objects/structseq.c
@@ -440,7 +440,7 @@
 	0,                        	        /* tp_print */
 	0,			 		/* tp_getattr */
 	0,					/* tp_setattr */
-	0,               			/* tp_compare */
+	0,               			/* tp_reserved */
 	(reprfunc)structseq_repr,             	/* tp_repr */
 	0,					/* tp_as_number */
 	&structseq_as_sequence,			/* tp_as_sequence */