Test $*KERNEL.signal: Str:D works
Test $*KERNEL.signal: Str:D works

...with un-initialized $*KERNEL.signals

Rakudo regression: https://github.com/rakudo/rakudo/commit/79b8ab9d3f
Rakudo fix: https://github.com/rakudo/rakudo/commit/01d948d2d2

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