message: alive: fix type printing
diff: @@ -277,9 +277,7 @@ static Type& get_overflow_type(Type &type) {
  }
  static Type& get_sym_type() {
  - if (sym_num < sym_types.size())
  - return *sym_types[sym_num++].get();
  -
  + // NOTE: don't reuse sym_types across transforms or printing is messed up
  return *sym_types.emplace_back(
  make_unique<SymbolicType>("symty_" + to_string(sym_num++))).get();
  }
  