Changes to ghc

Changes to ghc:
commit 41f803105999ffe51a40d3c72d5994520496b7ea
Author: Simon Peyton Jones <simonpj@microsoft.com>
Date:   Tue Mar 11 12:47:57 2014 +0000

    Fix last-minute typo in SetLevels commit ef44a4

    Sorry about that...