Changes to ghc(2)

Changes to ghc:
commit 2f5db98e90cf0cff1a11971c85f108a7480528ed
Author: Simon Marlow <marlowsd@gmail.com>
Date:   Mon Feb 18 14:34:26 2013 +0000

    Implement shortcuts for slow calls that would require PAPs (#6084)

commit 45eaeee3d7f5ef2efbc72769ebe6b988a867692a
Author: Simon Marlow <marlowsd@gmail.com>
Date:   Fri Oct 25 08:18:08 2013 +0100

    Another attempt to fix the conditions for slop-zeroing

    Also refactor the #defines to hopefully make it clearer what's going
    on.