message: Adding check around AddFunctionLibrary
diff: @@ -102,7 +102,8 @@ class PartitionedCallOp : public AsyncOpKernel {
  // by name.
  auto graph = tensorflow::MakeUnique<Graph>(fbody->graph->flib_def());
  FunctionLibraryDefinition global_flib(OpRegistry::Global(), {});
  - graph.get()->AddFunctionLibrary(global_flib.ToProto());
  + TF_CHECK_OK(
  + graph.get()->AddFunctionLibrary(global_flib.ToProto()));
  CopyGraph(*fbody->graph, graph.get());
  OP_REQUIRES_OK_ASYNC(ctx, PinResourceArgs(graph.get(), args), done);
  @@ -258,7 +259,8 @@ class PartitionedCallOp : public AsyncOpKernel {
  for (const auto& partition : partitions) {
  std::unique_ptr<Graph> subgraph(new Graph(graph->flib_def()));
  FunctionLibraryDefinition global_flib(OpRegistry::Global(), {});
  - subgraph.get()->AddFunctionLibrary(global_flib.ToProto());
  + TF_CHECK_OK(
  + subgraph.get()->AddFunctionLibrary(global_flib.ToProto()));
  GraphConstructorOptions opts;
  opts.allow_internal_ops = true;
  opts.expect_device_spec = true;
  