Changes to ghc(3)

Changes to ghc:
commit 8bf8ce1e7cb1b97a1f18ec6f5552e339808ffba9
Author: Simon Peyton Jones <simonpj@microsoft.com>
Date:   Thu Apr 3 13:34:52 2014 +0100

    Test Trac #8931

commit 3671d0027329804a31a628a5bee355e0640a2045
Author: Simon Peyton Jones <simonpj@microsoft.com>
Date:   Thu Apr 3 13:30:59 2014 +0100

    Fix desguaring of bang patterns (Trac #8952)

    A palpable bug, although one that will rarely bite

commit 791f4fa24dd6929ab2e55c9f8b870d8078337427
Author: Simon Peyton Jones <simonpj@microsoft.com>
Date:   Tue Apr 1 14:34:11 2014 +0100

    Make sure that polykinded Typeable is defaultable (Trac #8931)