[newlib-cygwin] Cygwin: add @cjksingle to release docs

[Corinna Vinschen <corinna@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=592b03b3ba0d51b1d3edda6302f324ecd53c83eb

commit 592b03b3ba0d51b1d3edda6302f324ecd53c83eb
Author: Corinna Vinschen <corinna@vinschen.de>
Date:   Tue Feb 18 11:32:47 2020 +0100

    Cygwin: add @cjksingle to release docs
    
    Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

Diff:
---
 winsup/cygwin/release/3.1.4 | 5 +++++
 winsup/doc/new-features.xml | 7 +++++++
 2 files changed, 12 insertions(+)

diff --git a/winsup/cygwin/release/3.1.4 b/winsup/cygwin/release/3.1.4
index 1c44954..2d44870 100644
--- a/winsup/cygwin/release/3.1.4
+++ b/winsup/cygwin/release/3.1.4
@@ -16,6 +16,11 @@ What changed:
 - <signal.h>: New macro _NSIG replacing NSIG.  NSIG is now only
   visible to MISC builds, as on Linux.
 
+- The new locale modifier @cjksingle allows enforcing of single-width
+  character property for usually double-widthed characters.  This will
+  be supported by upcoming mintty releases.  For the reasoning, see
+  https://gitlab.freedesktop.org/terminal-wg/specifications/issues/9.
+
 
 Bug Fixes:
 ----------
diff --git a/winsup/doc/new-features.xml b/winsup/doc/new-features.xml
index 78c7760..9086302 100644
--- a/winsup/doc/new-features.xml
+++ b/winsup/doc/new-features.xml
@@ -75,6 +75,13 @@ set, or if an attempt is made to open a different type of socket, the
 errno is now EOPNOTSUPP instead of ENXIO.
 </para></listitem>
 
+<listitem><para>
+The new locale modifier @cjksingle allows enforcing of single-width
+character property for usually double-widthed characters.  This will
+be supported by upcoming mintty releases.  For the reasoning, see
+https://gitlab.freedesktop.org/terminal-wg/specifications/issues/9.
+</para></listitem>
+
 </itemizedlist>
 
 </sect2>