Changes to ghc

Changes to ghc:
commit 2f6d36f64730f044bb038e2d3da2b97ee571d763
Author: Krzysztof Gogolewski <krz.gogolewski@gmail.com>
Date:   Tue Feb 4 23:42:00 2014 +0100

    Tweak holes documentation

    type holes -> typed holes, reorder, minor changes