Apply lizmat++'s improvements
Apply lizmat++'s improvements

From https://irclog.perlgeek.de/perl6-dev/2017-09-15#i_15169665

Makes .pred 2.8x faster still and .succ 80% faster

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