[wwwdocs] Document addition of C++ header in C++11

[Jonathan Wakely via Gcc-patches]

Pushed to wwwdocs.


commit 768ecbe7af00a219cfdff9fba96874a0fe9c94bb
Author: Jonathan Wakely <jwak...@redhat.com>
Date:   Thu Jan 14 10:41:43 2021 +0000

    Document addition of <barrier> C++ header in C++11

diff --git a/htdocs/gcc-11/changes.html b/htdocs/gcc-11/changes.html
index e044d710..3527428f 100644
--- a/htdocs/gcc-11/changes.html
+++ b/htdocs/gcc-11/changes.html
@@ -307,7 +307,8 @@ a work-in-progress.</p>
       <li><code>std::bit_cast</code></li>
       <li><code>std::source_location</code></li>
       <li>Atomic wait and notify operations.</li>
-      <li><code>&lt;latch&gt;</code> and <code>&lt;semaphore&gt;</code></li>
+      <li><code>&lt;barrier&gt;</code>, <code>&lt;latch&gt;</code>,
+        and <code>&lt;semaphore&gt;</code></li>
       <li><code>&lt;syncstream&gt;</code></li>
       <li>Efficient access to <code>basic_stringbuf</code>'s buffer.</li>
     </ul>