Can't call functions on arguments

[dburgener]

virtual domain parent {
    fn some_func(domain source) {
        allow(source, this, process, signal);
    }
}

domain child inherits parent {}

domain other {
    fn call_signal(parent to_call) {
        to_call.some_func(this);
    }
}

I think policy like the above isn't working now and should