message: major changes:
  1. fix crash when using run/test with -c opt.
diff: @@ -138,6 +138,7 @@ Status ShapeOptimizer::Optimize(Cluster* cluster, const GrapplerItem& item,
  graph.GetRegularFanin(MutableGraphView::InputPort(&node, 0));
  const MutableGraphView::OutputPort input2 =
  graph.GetRegularFanin(MutableGraphView::InputPort(&node, 1));
  + if (input1.node == nullptr || input2.node == nullptr) continue;
  if (!IsSize(*input1.node) || !IsSize(*input2.node)) {
  continue;
  }
  