dart2js needs to emit a static warning for the following use of a constant constructor:

class C {
  const C(int i);
}

main() {
  var c = const C('hest');
  print(c);
}

The static type of a constant object expression of either the form const T.id(a1, .., an) or the form const T(a1, .., an) is T. It is a static warning if the static type of ai, 1 <= i <= n+ k may not be assigned to the type of the corresponding formal parameter of the constructor T.id (respectively T).