Add example 'abstract' architectures for LLI: MIX, MMIX, and DLX


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16653 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/OpenProjects.html b/docs/OpenProjects.html
index b405081..15816b6 100644
--- a/docs/OpenProjects.html
+++ b/docs/OpenProjects.html
@@ -344,7 +344,10 @@
   <li>Convert the non-functional Skeleton target to become an abstract machine
   target (choose some simple instructions, a register set, etc).  This will
   become a much more useful example of a backend since it would be a simple
-  but <em>functional</em> backend.</li>
+  but <em>functional</em> backend.  Examples of such architectures include MIX,
+  MMIX, <a
+  href="http://www.cs.cinvestav.mx/SC/prof_personal/adiaz/vhdl/DLX/">DLX</a>,
+  or come up with your own!</li>
   <li>Use the new Skeleton backend in the Interpreter: compile LLVM to Skeleton
   target, and then interpret that code instead of LLVM.  Performance win would
   be the primary goal, as the number of registers would be a small constant