Speed up subbuf by using the new nqp::slice op...
Speed up subbuf by using the new nqp::slice op...

instead of manually looping with nqp::bindpos+nqp::atpos.

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