Cygwin: document last change

winsup/cygwin/release/3.1.0

@@ -30,6 +30,9 @@ What changed:
 - Eliminate a header file name collision with <X11/XLocale.h> on case
   insensitive filesystems by reverting <xlocale.h> back to <sys/_locale.h>.
 
+- Allow times(2) to have a NULL argument, as on Linux.
+  Addresses: https://cygwin.com/ml/cygwin/2019-09/msg00141.html
+
 
 Bug Fixes
 ---------

winsup/doc/new-features.xml

@@ -46,6 +46,10 @@ New APIs: dbm_clearerr, dbm_close, dbm_delete, dbm_dirfno, dbm_error,
 dbm_fetch, dbm_firstkey, dbm_nextkey, dbm_open, dbm_store.
 </para></listitem>
 
+<listitem><para>
+Allow times(2) to have a NULL argument, as on Linux.
+</para></listitem>
+
 </itemizedlist>
 
 </sect2>