Optional parameters in extension methods not working

[EotT123]

It appears that optional and named parameters in extension methods aren't functioning correctly.

public class Foo {}

@Extension
public class FooExt {
    public static String test(@This Foo foo, String bar="", String foobar){
        return bar + foobar;
    }
}

new Foo().test("bar", "foobar"); // OK
new Foo().test(bar:"bar", foobar:"foobar"); // NOK when using using named parameters
new Foo().test(foobar:"foobar"); // NOK when only supplying required parameter

[EotT123]

I've fixed the example, I forgot to add a default value for one of the parameters.

The following warning is also displayed: Maybe missing '@This' to declare an instance extension method?". The first parameter is clearly annotated with @This, but while using the debugger, I noticed that the annotation isn't present in the generated code.