Update release notes with 2 features now supported in -fms-extensions…

… mode.

I think that's enough for my release notes.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@145320 91177308-0d34-0410-b5e6-96231b3b80d8

docs/ReleaseNotes.html

@@ -192,6 +192,8 @@ <h4 id="windows">Clang is building and tested regularly on Windows and can
   <li>clang can now parse all the MSVC 2010 standard C++ header files
   in the nominal case, (still need to specifiy -nobuiltininc for some headers).</li>
   <li>Improved support for MFC code parsing, (still a work in progress).</li>
+  <li>Add support for function template specialization at class scope (-fms-extensions mode).</li>
+  <li>Add support for Microsoft __if_exists/__if_not_exists statements (-fms-extensions mode).</li>
 </ul>
 
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