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/PC/winreg.c b/PC/winreg.c
index 8a4a215..7e8ea10 100644
--- a/PC/winreg.c
+++ b/PC/winreg.c
@@ -485,7 +485,7 @@
 	0,				/* tp_print */
 	0,				/* tp_getattr */
 	0,				/* tp_setattr */
-	0,				/* tp_compare */
+	0,				/* tp_reserved */
 	0,				/* tp_repr */
 	&PyHKEY_NumberMethods,		/* tp_as_number */
 	0,				/* tp_as_sequence */