Changes to ghc

Changes to ghc:
commit b20bc181d8ba496f866c44ae65d26118c2c502a1
Author: Simon Peyton Jones <simonpj@microsoft.com>
Date:   Thu Apr 3 15:55:46 2014 +0100

    Parse the variables in a type signature in the order given (Trac #8945)

    This is just making the parser behave more sensibly, and return
    the list [x,y,z] from the signature
       x,y,z :: Int
    rathe than [x,z,y] as now.

    Turns out that the other use of sig_vars *did* do the right
    thing already.