Changes to ghc

Changes to ghc:
commit 6024c9f499ce54e4b9bd71b56588fd0bf6f7be97
Author: Austin Seipp <austin@well-typed.com>
Date:   Fri Oct 25 20:08:28 2013 -0500

    Release note blurb about ELF weak symbols.

    Signed-off-by: Austin Seipp <austin@well-typed.com>