Changes to ghc

Changes to ghc:
commit c1035d51edaac2f388a0630e2ad25391e7e3c1ab
Author: Herbert Valerio Riedel <hvr@gnu.org>
Date:   Tue Jun 24 11:42:06 2014 +0200

    Fix regression in Data.Fixed Read instance (re #9231)

    `convertFixed` operates under the wrong assumption that
    `Data.Fixed.resolution` returns a base-10 exponent `e`, whereas it
    actually returns the power-of-10 value `10^e`.

    So while the code (that was introduced in 5f19f951d8 / #7483) happens to
    compute a correct result by coincidence, it allocates huge integer values
    in the process (i.e. `10^(10^e)`) which cause long computations which
    eventually result in out-of-memory conditions for `e`-values beyond
    `Data.Fixed.Milli`.

    A proper long-term fix would probably be to extend the `HasResolution`
    type-class to have a 2nd method providing the `e` value.

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

    Differential Revision: https://phabricator.haskell.org/D25