add a couple of notes


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21754 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/ReleaseNotes.html b/docs/ReleaseNotes.html
index ed2632f..2845202 100644
--- a/docs/ReleaseNotes.html
+++ b/docs/ReleaseNotes.html
@@ -87,6 +87,8 @@
   <li>Configuring LLVM to build targets selectively is now implemented, via the
       <tt>--enable-targets=</tt> option. This feature is documented
       <a href="GettingStarted.html#config">here</a>.</li>
+  <li>LLVM now supports <a href="LangRef.html#callingconv">custom and
+      target-specific calling conventions</a>.</li>
 </ol>
 
 </div>