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/Modules/_threadmodule.c b/Modules/_threadmodule.c
index f0d03d7..a031998 100644
--- a/Modules/_threadmodule.c
+++ b/Modules/_threadmodule.c
@@ -129,7 +129,7 @@
 	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*/
@@ -358,7 +358,7 @@
 	/* 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    */ 0,