Implement R:It.native_s/i/n for iterating native lists
Implement R:It.native_s/i/n for iterating native lists

- can be used for nqp::list_s/i/n as well as str/int/num arrays
- are PredictiveIterators, rather than the ones in native_array
- to be used in the core where they make sense

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