SF bug #487743: test_builtin fails on 64 bit platform.

Bugfix candidate.
int_repr():  we've never had a buffer big enough to hold the largest
possible result on a 64-bit box.  Now that we're using snprintf instead
of sprintf, this can lead to nonsense results instead of random stack
corruption.

Objects/intobject.c

@@ -258,7 +258,7 @@ int_print(PyIntObject *v, FILE *fp, int flags)
 static PyObject *
 int_repr(PyIntObject *v)
 {
-	char buf[20];
+	char buf[64];
 	PyOS_snprintf(buf, sizeof(buf), "%ld", v->ob_ival);
 	return PyString_FromString(buf);
 }