message: In Mesh::CheckBdrElementOrientation, in 2D, generate the edge/face
  internal data, if not already generated.
diff: @@ -3784,6 +3784,12 @@ int Mesh::CheckBdrElementOrientation(bool fix_it)
  if (Dim == 2)
  {
  + if (el_to_edge == NULL) // edges were not generated
  + {
  + el_to_edge = new Table;
  + NumOfEdges = GetElementToEdgeTable(*el_to_edge, be_to_edge);
  + GenerateFaces(); // 'Faces' in 2D refers to the edges
  + }
  for (int i = 0; i < NumOfBdrElements; i++)
  {
  if (faces_info[be_to_edge[i]].Elem2No < 0) // boundary face
  