message: Create new order on replica clone
  Test Plan: it doesn't take a long time on that example
  Reviewers: jakeh, davidn, stephenm
diff: #include "tensorflow/compiler/xla/service/hlo_query.h"
  #include "tensorflow/compiler/xla/window_util.h"
  +#include <poplar/TensorCloneMethod.hpp>
  #include <popnn/Pooling.hpp>
  #include <popnn/PoolingDef.hpp>
  #include <popops/Cast.hpp>
  @@ -950,7 +951,9 @@ StatusOr<poplar::program::Program> CreateReplicatedAllReduce(
  auto t = poplar::concat(flat_tensors);
  if (tensorflow::GetPoplarXlaFlags().add_all_reduce_copies) {
  // TODO T8856 - remove this flag.
  - auto t_cloned = res.replicated_graph->clone(t);
  + auto t_cloned = res.replicated_graph->clone(
  + t, GetDebugName(inst) + "/Copy",
  + poplar::TensorCloneMethod::CREATE_NEW_ORDER);
  seq.add(poplar::program::Copy(t, t_cloned));
  t = t_cloned;
  }
  