message: Remove code that prevents control flow ops being functionalized
diff: @@ -454,13 +454,6 @@ Status MarkForCompilationPass::RunImpl(
  worklist.pop_front();
  Node* node_from = graph->FindNodeId(from);
  - if (node_from->IsControlFlow()) {
  - // Control flow nodes aren't compilation candidates and should never
  - // appear.
  - return errors::Internal(
  - "Found control flow node in clustering worklist: ",
  - node_from->type_string());
  - }
  string from_scope;
  string to_scope;
  for (int to : cycles.Successors(from)) {
  