TH doesn't pretty-print classes without fundeps correctly

[greenrd]

A class with no functional dependencies is pretty-printed with a spurious | character, like in this example:

class Abstraction c_0 a_1 |
    where abstractL :: forall m_2 . GHC.Base.Monad m_2 => c_0 ->
                                                          Control.Monad.State.StateT ([(Ident,
                                                                                        Term)])
                                                                                     m_2
                                                                                     a_1

[igloo]

Fixed (in HEAD and 6.6 branch) by a patch from Stefan O'Rear.

Thanks for the report!