The index stored in the RegDefIter is one after the current index. When getting the index, decrement it so that it points to the current element. Fixes an off-by-one bug encountered when trying to make use of MVT::untyped.

llvm-svn: 133923

llvm/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.h

@@ -140,7 +140,7 @@ namespace llvm {
       }
 
       unsigned GetIdx() const {
-        return DefIdx;
+        return DefIdx-1;
       }
 
       void Advance();