Add note that some of these links are dead for now.

llvm-svn: 179950
diff --git a/clang/www/cxx_status.html b/clang/www/cxx_status.html
index bfa612e..edd93e7 100644
--- a/clang/www/cxx_status.html
+++ b/clang/www/cxx_status.html
@@ -405,6 +405,9 @@
 have been implemented in Clang and in which Clang version they became
 available.</p>
 
+<p>Note: many of the links to papers here will not work until the
+ISO/IEC JTC1/SC22/WG21 post-Bristol mailing ships.</p>
+
 <table width="689" border="1" cellspacing="0">
  <tr>
     <th>Language Feature</th>