Changes to ghc

Changes to ghc:
commit 26f41922e8923185bc77ceb8ef44d23564d29bed
Author: Herbert Valerio Riedel <hvr@gnu.org>
Date:   Sun Jun 29 16:06:45 2014 +0200

    Promote TcNullaryTC and TcCoercible to fast tests

    I'm wondering whether it's sensible to omit so many typecheck testcases from
    the default validate test target. As for instance, TcNullaryTC has been failing
    since its introduction in c63a465011b99eeafbb957074e54c2e6bbf751d9 (re #8993) and
    it seems to have gone unnoticed so far.

    Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>