Shorten R:Q.MIX-IS-SUBSET a bit
Shorten R:Q.MIX-IS-SUBSET a bit

nqp::iterator also returns false on an empty nqp::hash

Gnouc/rakudo,tbrowder/rakudo,labster/rakudo,tony-o/rakudo,lucasbuchala/rakudo,raydiak/rakudo,salortiz/rakudo,Gnouc/rakudo,usev6/rakudo,labster/rakudo,rakudo/rakudo,softmoth/rakudo,rakudo/rakudo,softmoth/rakudo,tbrowder/rakudo,tbrowder/rakudo,raydiak/rakudo,salortiz/rakudo,labster/rakudo,softmoth/rakudo,nbrown/rakudo,nbrown/rakudo,awwaiid/rakudo,nbrown/rakudo,tbrowder/rakudo,salortiz/rakudo,jonathanstowe/rakudo,raydiak/rakudo,Gnouc/rakudo,nbrown/rakudo,MasterDuke17/rakudo,sjn/rakudo,awwaiid/rakudo,sjn/rakudo,usev6/rakudo,awwaiid/rakudo,usev6/rakudo,jonathanstowe/rakudo,lucasbuchala/rakudo,labster/rakudo,MasterDuke17/rakudo,nbrown/rakudo,jonathanstowe/rakudo,salortiz/rakudo,lucasbuchala/rakudo,awwaiid/rakudo,awwaiid/rakudo,tbrowder/rakudo,MasterDuke17/rakudo,labster/rakudo,softmoth/rakudo,sjn/rakudo,MasterDuke17/rakudo,Gnouc/rakudo,lucasbuchala/rakudo,rakudo/rakudo,usev6/rakudo,tbrowder/rakudo,Gnouc/rakudo,softmoth/rakudo,salortiz/rakudo,tony-o/rakudo,MasterDuke17/rakudo,jonathanstowe/rakudo,salortiz/rakudo,tony-o/rakudo,nbrown/rakudo,sjn/rakudo,labster/rakudo,tony-o/rakudo,tony-o/rakudo,lucasbuchala/rakudo,rakudo/rakudo,rakudo/rakudo,usev6/rakudo,tony-o/rakudo,raydiak/rakudo,rakudo/rakudo,Gnouc/rakudo,sjn/rakudo,MasterDuke17/rakudo,jonathanstowe/rakudo