Changes to ghc

Changes to ghc:
commit a15d243e4c15c45a401dec8c30a5135b6b006115
Author: Herbert Valerio Riedel <hvr@gnu.org>
Date:   Tue May 20 09:40:36 2014 +0200

    Harden imports in `DeriveConstants.hs` module

    This was generated by applying `-ddump-minimal-imports` and addresses
    the current compile failure (see #9016) with GHC HEAD due to the new
    `die` being exported by `System.Exit`

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