[wwwdocs] Document more C++2a support in libstdc++

[Jonathan Wakely]

Committed to CVS.



? htdocs/gcc-9/.changes.html.swp
Index: htdocs/gcc-9/changes.html
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-9/changes.html,v
retrieving revision 1.10
diff -u -r1.10 changes.html
--- htdocs/gcc-9/changes.html	2 Jul 2018 16:08:32 -0000	1.10
+++ htdocs/gcc-9/changes.html	4 Jul 2018 20:16:09 -0000
@@ -60,8 +60,11 @@
 <h4 id="libstdcxx">Runtime Library (libstdc++)</h4>
 <ul>
   <li>Improved experimental support for C++2a,
-      including <code>std::remove_cvref</code>
-      and the <code>&lt;version&gt;</code> header.</li>
+      including type traits <code>std::remove_cvref</code>,
+      <code>std::is_trivially_convertible</code>, and
+      <code>std::type_identity</code>,
+      and headers <code>&lt;bit&gt;</code> and <code>&lt;version&gt;</code>.
+  </li>
   <li>Support for opening file streams with wide character paths on Windows</li>
   <li>Incomplete support for the C++17 Filesystem library and the Filesystem
       TS on Windows.</li>