[m-rev.] diff: add reverse modes for uint.xor/2 (part 2)

[Julien Fischer]

This requires rotd-2017-05-31 or later.

-------------------

Add reverse modes for uint.xor/2 (part 2).

library/uint.m:
       Uncomment the declarations for the reverse modes of xor/2.

Julien.

diff --git a/library/uint.m b/library/uint.m
index 5f1776b9b..f58dd73d5 100644
--- a/library/uint.m
+++ b/library/uint.m
@@ -163,8 +163,8 @@
      %
  :- func xor(uint, uint) = uint.
  :- mode xor(in, in) = uo is det.
-%:- mode xor(in, uo) = in is det.
-%:- mode xor(uo, in) = in is det.
+:- mode xor(in, uo) = in is det.
+:- mode xor(uo, in) = in is det.

      % Bitwise complement.
      %