Streamline generic handling of (<+) (>+)
Streamline generic handling of (<+) (>+)

Making it about 15% faster: mostly because of using .AT-KEY, thereby
skipping the {} step.

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