message: Fix the bug that fallback does not support more than one output
diff: @@ -280,9 +280,21 @@ GraphAndMapping ConstructFallbackGraph(
  }
  }
  + if (block->outputs().size() > 1){
  + std::vector<torch::jit::Value*> fallback_graph_vector;
  for (auto& output : block->outputs()){
  if (old_to_new_g.count(output)) {
  - new_g->registerOutput(old_to_new_g[output]);
  + fallback_graph_vector.push_back(old_to_new_g[output]);
  + }
  + }
  + torch::jit::ArrayRef<torch::jit::Value*> fallback_graph_outputs(fallback_graph_vector);
  + auto return_tuple_node = new_g->createTuple(fallback_graph_outputs);
  + new_g->block()->appendNode(return_tuple_node);
  + // Set the output as the produced tuple
  + new_g->registerOutput(return_tuple_node->outputs()[0]);
  + } else {
  + if (old_to_new_g.count(block->outputs()[0])) {
  + new_g->registerOutput(old_to_new_g[block->outputs()[0]]);
  }
  }
  return {new_g, old_to_new_g};
  