message: Use a clone method for creating the reduction tensor in select and scatter
diff: @@ -476,13 +476,21 @@ CreateSimpleSelectAndScatter(poplar::Graph &graph,
  int64 overlap_count(std::accumulate(overlap.begin(), overlap.end(), 1,
  [](int64 a, int64 b) { return a * b; }));
  + // Create a partials tensor for reduction
  + std::vector<std::size_t> poplar_shape = operand.shape();
  + poplar_shape.push_back(1);
  +
  + poplar::Tensor extended_operand = operand.reshape(poplar_shape);
  + poplar::Tensor partial = graph.clone(extended_operand);
  +
  + for (int64 i=1; i<overlap_count; i++) {
  + partial = poplar::concat(partial, graph.clone(extended_operand), partial.rank() - 1);
  + }
  +
  xla::Shape partial_shape(output_shape);
  partial_shape.add_dimensions(overlap_count);
  LayoutUtil::ClearLayout(&partial_shape);
  - poplar::Tensor partial;
  - TF_ASSIGN_OR_RETURN(partial, AddPlainTensor(graph, inst, partial_shape));
  -
  Literal identity_literal = GetIdentityConstantLiteral(scatter_root);
  poplar::Tensor identity_val;
  