Added test for async bug
Added test for async bug

rakudo/rakudo#1202

MasterDuke17/rakudo,labster/rakudo,salortiz/rakudo,labster/rakudo,MasterDuke17/rakudo,rakudo/rakudo,MasterDuke17/rakudo,tony-o/rakudo,tony-o/rakudo,tony-o/rakudo,nbrown/rakudo,tony-o/rakudo,tbrowder/rakudo,salortiz/rakudo,tbrowder/rakudo,salortiz/rakudo,nbrown/rakudo,tbrowder/rakudo,softmoth/rakudo,labster/rakudo,nbrown/rakudo,rakudo/rakudo,nbrown/rakudo,rakudo/rakudo,softmoth/rakudo,MasterDuke17/rakudo,rakudo/rakudo,MasterDuke17/rakudo,softmoth/rakudo,salortiz/rakudo,tony-o/rakudo,labster/rakudo,nbrown/rakudo,tony-o/rakudo,labster/rakudo,rakudo/rakudo,nbrown/rakudo,tbrowder/rakudo,MasterDuke17/rakudo,softmoth/rakudo,salortiz/rakudo,rakudo/rakudo,softmoth/rakudo,salortiz/rakudo,tbrowder/rakudo,tbrowder/rakudo,labster/rakudo