Add Nil tests for $/, $!, $_
Add Nil tests for $/, $!, $_

laben/roast,laben/roast,bitrauser/roast,cygx/roast,zostay/roast,perl6/roast,dogbert17/roast,bitrauser/roast,skids/roast,zostay/roast,niner/roast,dogbert17/roast,cygx/roast,niner/roast,niner/roast,skids/roast,zostay/roast,b2gills/roast,skids/roast,dankogai/roast,b2gills/roast,dankogai/roast,b2gills/roast,laben/roast,cygx/roast,dankogai/roast