Changes to ghc

Changes to ghc:
commit 8992d5269804b727fb77249511e89df678526907
Author: Herbert Valerio Riedel <hvr@gnu.org>
Date:   Tue Apr 15 11:09:45 2014 +0200

    Update Cabal submodule to tip of v1.20 branch

    This corresponds to the RC of the soon-to-be Cabal 1.20 release

    One noteworthy change is the removal of the `--with-ranlib` flag
    requiring a small adaptation in the GHC build system.

    Moreover two new licences were added, MPL and BSD2.

    Due to https://github.com/haskell/cabal/issues/1622 Cabal-1.20 now
    allows to strip libraries as well, this doesn't work well with
    `ghc-cabal copy` being fed a `":"` strip-command argument which was
    simply ignored in the past. The current code tries to retain this
    semantics as backward compat. However, this needs more investigation as
    I'm not sure if/why the `test_bindist` step doesn't want the libraries
    to be stripped on installation.

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