Changes to ghc

Changes to ghc:
commit e7b9c4125321308a7f71cacf4c24b7d40261ccfd
Author: Krzysztof Gogolewski <krz.gogolewski@gmail.com>
Date:   Tue Jul 1 20:19:20 2014 +0200

    Fixup nullary typeclasses (Trac #8993)

    Summary: Fix test broken after Trac #8993

    Test Plan: validate

    Reviewers: austin, simonpj, hvr

    Reviewed By: austin, hvr

    Subscribers: simonmar, relrod, carter

    Differential Revision: https://phabricator.haskell.org/D34