[m-rev.] for review: announce 64-bit MSVC support

[Julien Fischer]

For review by anyone.

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

Announce 64-bit MSVC support.

NEWS.md:
     As above.

Julien.

diff --git a/NEWS.md b/NEWS.md
index f396948..6fd1fe3 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -2033,6 +2033,9 @@ Changes to the Mercury compiler
  Portability improvements
  ------------------------

+* We now support using the 64-bit (i.e. x64) version of Microsoft Visual C++
+  as a C compiler with Mercury. See README.MS-VisualC.md for further details.
+
  * We have ported Mercury to Linux AArch64 (ARM64) systems.

  * The `tools/configure_mingw_cross` script has been replaced by