message: Remove the assertion on the exclude_types
diff: @@ -409,7 +409,9 @@ void Model::create_mergers_helper(
  void Model::exclude_types(const ConstTypeHashSet& exclude_types) {
  for (const auto& type : exclude_types) {
  const auto& cls = type_class(type);
  - redex_assert(cls != nullptr);
  + if (cls == nullptr) {
  + continue;
  + }
  if (is_interface(cls)) {
  const auto& impls = m_type_system.get_implementors(type);
  m_excluded.insert(impls.begin(), impls.end());
  