Test `Empty` as arg to andthen/postfix with
Test `Empty` as arg to andthen/postfix with

RT#130798: https://rt.perl.org/Ticket/Display.html?id=130798
Rakudo fix: https://github.com/rakudo/rakudo/commit/3c8822e80d

bitrauser/roast,bitrauser/roast,perl6/roast,dogbert17/roast,dogbert17/roast