Fix -Wcast-qual warnings.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101655 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
index e7ab2f0..50defc8 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
@@ -353,8 +353,8 @@
         const SDep& dep = SDep(OpSU, isChain ? SDep::Order : SDep::Data,
                                OpSU->Latency, PhysReg);
         if (!isChain && !UnitLatencies) {
-          ComputeOperandLatency(OpSU, SU, (SDep &)dep);
-          ST.adjustSchedDependency(OpSU, SU, (SDep &)dep);
+          ComputeOperandLatency(OpSU, SU, const_cast<SDep &>(dep));
+          ST.adjustSchedDependency(OpSU, SU, const_cast<SDep &>(dep));
         }
 
         SU->addPred(dep);