[js] Use --> syntax instead of returns
[js] Use --> syntax instead of returns

Make the code look more like the rest of the setting

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