Cannot implement abstract method with extension method

[Thomas Jung]

> I see. This looks more like a bug, but what about the following:
>
> interface A{
>        extension boolean m(Object object) default As.m;
> }
> interface B {
>        extension boolean m(Object object) default Bs.m;
> }
>
> class C  implements A, B{}

That's clearly ambiguous.

Thomas