Push PrepareNodeInfo/IdentifyGroups down the inheritance hierarchy

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26682 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/SelectionDAG/ScheduleDAG.cpp

@@ -498,10 +498,6 @@ MachineBasicBlock *ScheduleDAG::Run() {
 
   // Number the nodes
   NodeCount = std::distance(DAG.allnodes_begin(), DAG.allnodes_end());
-  // Set up minimum info for scheduling
-  PrepareNodeInfo();
-  // Construct node groups for flagged nodes
-  IdentifyGroups();
 
   Schedule();
   return BB;