builtin type as return type of function

[kanigsson]

The following session:

package Empty_Ident is

  type My_Int is mod 2 ** 8;
   generic
      with function Output (X : My_Int) return Boolean;
   session Session with
      Initial => First,
      Final => Last
   is
     X : My_Int;
     Z : Boolean;
   begin
      state First is
      begin
        X := 1;
        Z := Output (X);
      transition
         then Last
      end First;

      state Last is null state;
   end Session;
end Empty_Ident;

produces an unhelpful error:

Parsing empty_ident.rflx
Processing Empty_Ident
id: error: empty identifier

I think the issues is with return types of functions. I will try to fix this.