message: [Grappler] Fix bug in arithmetic optimizer causing non-unique node names.
diff: @@ -887,7 +887,8 @@ class HoistCommonFactorOutOfAggregation : public ArithmeticOptimizerStage {
  // them, it's possible that rewritten node already exists in a graph
  return rewritten_nodes_.find(node->name()) != rewritten_nodes_.end() ||
  ctx().node_map->NodeExists(OuterNodeName(node, false)) ||
  - ctx().node_map->NodeExists(OuterNodeName(node, true));
  + ctx().node_map->NodeExists(OuterNodeName(node, true)) ||
  + ctx().node_map->NodeExists(InnerAddNodeName(node));
  }
  // keep names of the nodes that were optimized by this stage
  