Fix for RT #130458
Fix for RT #130458

Spotted by AlexDaniel++, this patch reverts to the old behaviour
of interpreting a Uni as a .Str for regex matching.  Still not sure
that's what we want, but since we have now isolated this behaviour
into a separate Regex.ACCEPTS candidate (it was formerly taken by
the @a candidate), an adaptation of behaviour should now be simple
if so needed.

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