Streamline .grep adverb handling
Streamline .grep adverb handling

Reduces the overhead by 10% (no adverbs) to 30% (:v adverb) by
using the underlying native hash for checking.

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