SelectionDAG: Avoid implicit iterator conversions in ScheduleDAGSDNodes, NFC

llvm-svn: 274903
diff --git a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
index c71163c..3be622f 100644
--- a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
@@ -750,7 +750,7 @@
     return;
   }
 
-  Orders.push_back(std::make_pair(Order, std::prev(Emitter.getInsertPos())));
+  Orders.push_back(std::make_pair(Order, &*std::prev(Emitter.getInsertPos())));
   ProcessSDDbgValues(N, DAG, Emitter, Orders, VRBaseMap, Order);
 }