Add a link to the "writing an optimization" tutorial.

llvm-svn: 43243

llvm/docs/tutorial/index.html

@@ -36,6 +36,10 @@
     <li>Extending the language: mutable variables</li>
     <li>Thoughts and ideas for extensions</li>
   </ol></li>
+  <li>Advanced Topics
+  <ol>
+    <li><a href="http://llvm.org/pubs/2004-09-22-LCPCLLVMTutorial.html">Writing an Optimization for LLVM</a></li>
+  </ol></li>
 </ol>
 
 </body>