Finish off bug 680, allowing targets to custom lower frame and return
address nodes.

llvm-svn: 33636
diff --git a/llvm/lib/Target/Alpha/AlphaISelLowering.cpp b/llvm/lib/Target/Alpha/AlphaISelLowering.cpp
index f0e5be6..7df996d 100644
--- a/llvm/lib/Target/Alpha/AlphaISelLowering.cpp
+++ b/llvm/lib/Target/Alpha/AlphaISelLowering.cpp
@@ -544,6 +544,9 @@
     return DAG.getTruncStore(S1, DAG.getConstant(VarArgsOffset, MVT::i64),
                              SA2, NULL, 0, MVT::i32);
   }
+  // Frame & Return address.  Currently unimplemented
+  case ISD::RETURNADDR:         break;
+  case ISD::FRAMEADDR:          break;
   }
 
   return SDOperand();