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/_sqlite/cache.c b/Modules/_sqlite/cache.c
index ed53958..7ac043c 100644
--- a/Modules/_sqlite/cache.c
+++ b/Modules/_sqlite/cache.c
@@ -282,7 +282,7 @@
         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 */
@@ -324,7 +324,7 @@
         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 */