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/weakrefobject.c b/Objects/weakrefobject.c
index aa65573..214dd95 100644
--- a/Objects/weakrefobject.c
+++ b/Objects/weakrefobject.c
@@ -342,7 +342,7 @@
     0,	                        /*tp_print*/
     0,                          /*tp_getattr*/
     0,                          /*tp_setattr*/
-    0,	                        /*tp_compare*/
+    0,	                        /*tp_reserved*/
     (reprfunc)weakref_repr,     /*tp_repr*/
     0,                          /*tp_as_number*/
     0,                          /*tp_as_sequence*/
@@ -642,7 +642,7 @@
     0,				        /* tp_print */
     0,				        /* tp_getattr */
     0, 				        /* tp_setattr */
-    0,				        /* tp_compare */
+    0,				        /* tp_reserved */
     (reprfunc)proxy_repr,	        /* tp_repr */
     &proxy_as_number,		        /* tp_as_number */
     &proxy_as_sequence,		        /* tp_as_sequence */
@@ -675,7 +675,7 @@
     0,				        /* tp_print */
     0,				        /* tp_getattr */
     0, 				        /* tp_setattr */
-    0,				        /* tp_compare */
+    0,				        /* tp_reserved */
     (unaryfunc)proxy_repr,	        /* tp_repr */
     &proxy_as_number,		        /* tp_as_number */
     &proxy_as_sequence,		        /* tp_as_sequence */