message: Fix compilation issue with clang 12
diff: @@ -127,7 +127,7 @@ class CFA {
  template <class BB>
  bool CFA<BB>::FindInWorkList(const std::vector<block_info>& work_list,
  uint32_t id) {
  - for (const auto b : work_list) {
  + for (const auto& b : work_list) {
  if (b.block->id() == id) return true;
  }
  return false;
  