As jmerelo++ pointed out [1] the statement prefix 'lazy' has been fixed back in 2015 with https://github.com/rakudo/rakudo/commit/d043961414. It no longer shares the implementation with 'do'.
The tests that are fudged with this ticket don't work, though. The test file S04-statements/lazy.t is not part of Rakudo's t/spectest.data. [1] https://github.com/perl6/roast/issues/528
