[perl #124630] Roast rakudo skip/todo test:./S02-magicals/dollar-underscore.t line:19 reason: 'for() with nullary block'

[Christian Bartolomaeus via RT]

The code used in this test died with X::AdHoc ("Too many positionals passed; 
expected 0 arguments but got 1").

That is right thing, so I adjusted and unfudged the test with commit 
https://github.com/perl6/roast/commit/f6fb6ab810