Changes to ghc

Changes to ghc:
commit 9d7cbbcf625bc103d9fd086e9fcf99cb5c4b56ea
Author: Joachim Breitner <mail@joachim-breitner.de>
Date:   Wed Dec 4 15:47:49 2013 +0000

    Remove code that generates FunDep error message context

    as it seems that this code is now dead (due to
    [Dropping derived constraints]) (See #8592)