message: Give an error instead of crashing when tfcompile is fed a tensor that is not
  needed for the fetch.
diff: @@ -93,8 +93,17 @@ Status AddArgNodes(Graph* graph, const NodeMap& node_map,
  // All feeds have been replaced by placeholders.
  const int output_index = 0;
  - const auto remap_it = feed_remapping.find(TensorIdToString(feed.id()));
  + const string key = TensorIdToString(feed.id());
  + const auto remap_it = feed_remapping.find(key);
  auto node_it = node_map.find(remap_it->second);
  + if (node_it == node_map.end()) {
  + // Strip off the aot_feed_#/ prefix.
  + StringPiece name(remap_it->second);
  + const auto index = name.find('/');
  + if (index > 0) name.remove_prefix(index + 1);
  + return errors::InvalidArgument(
  + "Node is fed but not needed for fetching: ", name);
  + }
  const Node* feed_node = node_it->second;
  // TODO(toddw): Invoke shape inference in AddPlaceholdersForFeeds and add a
  