Changes to ghc(2)

Changes to ghc:
commit a79613a75c7da0d3d225850382f0f578a07113b5
Author: Simon Peyton Jones <simonpj@microsoft.com>
Date:   Fri Mar 14 22:55:26 2014 +0000

    Revert ad15c2, which causes Windows seg-faults (Trac #8834)

    We don't yet understand WHY commit ad15c2, which is to do with
    CmmSink, causes seg-faults on Windows, but it certainly seems to.  So
    reverting it is a stop-gap, but we need to un-block the 7.8 release.

    Many thanks to awson for identifying the offending commit.

commit 7a7af1ffc48f605cf365faf8fcef31ef4f13822b
Author: Simon Peyton Jones <simonpj@microsoft.com>
Date:   Fri Mar 14 22:51:20 2014 +0000

    Unflatten the constraints of an inferred types (Trac #8889)

    There was even a comment to warn about this possiblity,
    and it finally showed up in practice!  This patch fixes
    it quite nicely, with commens to explain.