Changes to ghc

Changes to ghc:
commit 5ffc68bb75d34414987b5d1e5aa4f9061a7a7383
Author: Simon Marlow <marlowsd@gmail.com>
Date:   Fri Jun 13 16:57:16 2014 +0100

    Fix recomputation of TypeRep in the instance for Typeable (s a) (#9203)

    Summary:
    Every time we called typeRep on a type application, we were
    recomputing the TypeRep.  This showed up in a benchmark I had: #9203.

    Test Plan: Benchmark from #9203.

    Reviewers: simonpj, austin

    Subscribers: simonmar, relrod

    Differential Revision: https://phabricator.haskell.org/D19