[CodeGen] Disable default copy ctor and copy assignment operator for class Circuits

llvm/include/llvm/CodeGen/MachinePipeliner.h

class SwingSchedulerDAG : public ScheduleDAGInstrs {
   public:
     Circuits(std::vector<SUnit> &SUs, ScheduleDAGTopologicalSort &Topo)
         : SUnits(SUs), Blocked(SUs.size()), B(SUs.size()), AdjK(SUs.size()) {
       Node2Idx = new std::vector<int>(SUs.size());
       unsigned Idx = 0;
       for (const auto &NodeNum : Topo)
         Node2Idx->at(NodeNum) = Idx++;
     }
-
+    Circuits &operator=(const Circuits &other) = delete;
+    Circuits(const Circuits &other) = delete;
     ~Circuits() { delete Node2Idx; }
 
     /// Reset the data structures used in the circuit algorithm.
     void reset() {
       Stack.clear();
       Blocked.reset();
       B.assign(SUnits.size(), SmallPtrSet<SUnit *, 4>());
       NumPaths = 0;