Keep y a Py_hash_t instead of Py_uhash_t as it is compared with == -1 and the
compiler logic will do the right thing with just x as a Py_uhash_t.  This
matches what was already done in the 3.3 version.

cleanup only - no functionality or hash values change.
diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
index c725227..9e914cb 100644
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -315,7 +315,8 @@
 static Py_hash_t
 tuplehash(PyTupleObject *v)
 {
-    register Py_uhash_t x, y;  /* Unsigned for defined overflow behavior. */
+    register Py_uhash_t x;  /* Unsigned for defined overflow behavior. */
+    register Py_hash_t y;
     register Py_ssize_t len = Py_SIZE(v);
     register PyObject **p;
     Py_uhash_t mult = _PyHASH_MULTIPLIER;