Get rid of re-implementation of sortBy
Get rid of re-implementation of sortBy

I have no idea what this was doing lying around here, and due to the
usage of tuples it's actually slower, too.

Signed-off-by: Mateusz Kowalczyk <eefa6dfc1eac2904477d70db04ec6889dd790721@fuuzetsu.co.uk>

ghcjs/haddock-internal,ghcjs/haddock-internal