[m-rev.] diff: another update for the release notes

[Julien Fischer]

Another update for the release notes.

RELEASE_NOTES:
    Mention the versions of Windows we have tested on.

    Mention that Mercury ran on Windows XP in the past.

Julien.

diff --git a/RELEASE_NOTES b/RELEASE_NOTES
index 5525ef7..ba50b09 100644
--- a/RELEASE_NOTES
+++ b/RELEASE_NOTES
@@ -146,11 +146,12 @@ for further details.

  The current Mercury system has been tested on Linux (x86 and x86_64),
  macOS (x86_64), and Windows (x86 and x86_64).
+For Windows, we have tested this release on Windows 7 and Windows 10.

  In the past Mercury has also been known to run on: Digital Unix,
  OSF1, IRIX 5.x, Ultrix 4.3, BSDI 1.1, AIX, HPUX, Linux (Alpha),
  Compaq Tru64 Unix (Alpha), Solaris 2.7 (SPARC), Solaris (9),
-Mac OS X (PowerPC) and Windows 95, 98, ME, NT and 2000.
+Mac OS X (PowerPC) and Windows 95, 98, ME, NT, 2000 and XP.

  It should run without too many changes on other Unix variants as well.
  If you do encounter any problems, please report them to us via the