Changes to ghc

Changes to ghc:
commit 15b1eb7c67e29c4ad6f6859f89d220b33493fd46
Author: Austin Seipp <austin@well-typed.com>
Date:   Mon Mar 24 02:14:09 2014 -0500

    Revert "change deriveConstants to use nm in a POSIX way (fixes #8781)"

    It causes a failure on Windows right now.

    This reverts commit 045b28033a33a48d31951240a8cb35f2b78345dc.