InstanceInvokeMetaCapability doesn't let you invoke methods on super classes/mixins

[jakemac53]

For example the following throws when it shouldn't.

import 'package:reflectable/reflectable.dart';

class MyReflectable extends Reflectable {
  const MyReflectable()
      : super(const InstanceInvokeMetaCapability(IsReflectable));
}

const myReflectable = const MyReflectable();

class IsReflectable {
  const IsReflectable();
}

@myReflectable
class A {
  @IsReflectable()
  String get hello => 'world';
}

@myReflectable
class B extends A {}

main() {
  var instance = new B();
  var instanceMirror = myReflectable.reflect(instance);
  print(instanceMirror.invokeGetter('hello'));
}