Changes to ghc

Changes to ghc:
commit 2ba1a560a92f4de0938d03c48b0f2e00e382d6b6
Author: Iavor S. Diatchki <diatchki@galois.com>
Date:   Wed Jun 18 10:21:06 2014 -0700

    Only comments:  add notes explaining the various oddities of the `Typeable` implementation for type-level literals.