tests/compiler/dart2js/cps_ir/input/constructor_6.dart

class Bar {
  Bar(x, {y, z: 'z', w: '_', q}) {
    print(x);
    print(y);
    print(z);
    print(w);
    print(q);
  }
}
class Foo extends Bar {
  Foo() : super('x', y: 'y', w: 'w');
}
main() {
  new Foo();
}