message: [TF:XLA] Replace PlaceHolderV2 operations created by AddPlaceholdersForFeeds
  with PlaceHolder operations.
  This is because PlaceHolderV2 is already deprecated and the MLIR path doesn't
  handle it. See REGISTER_OP("PlaceholderV2") in array_ops.cc.
diff: @@ -402,7 +402,7 @@ Status AddPlaceholdersForFeeds(
  // TODO(shikharagarwal): Add original node information.
  NodeDef* d = graph_def->add_node();
  d->set_name(info.placeholder_name);
  - d->set_op("PlaceholderV2");
  + d->set_op("Placeholder");
  auto& attr_map = *d->mutable_attr();
  attr_map["dtype"].set_type(info.data_type);
  *attr_map["shape"].mutable_shape() = info.feed->shape();
  