Changes to ghc

Changes to ghc:
commit 9785bb7cb96ecee409a40fb413035758dd278db7
Author: Reid Barton <rwbarton@gmail.com>
Date:   Mon Jun 30 22:11:03 2014 -0400

    Add a cast to new code in hp2ps

    For parallelism with the existing code. I don't think it should
    make any difference.