Changes to ghc(2)

Changes to ghc:
commit f0af58df4b5d5ace750e7d7a91ad471284c1b429
Author: Austin Seipp <austin@well-typed.com>
Date:   Fri Apr 4 10:33:14 2014 -0500

    windows: Fix #8870

    This bumps the amount of default reserved and committed stack for GHC
    executables to 8mb, to work around #8870. A proper fix should happen in
    7.8.2

    See note [Windows stack usage] in SysTools for the details.

    Signed-off-by: Austin Seipp <austin@well-typed.com>

commit c6c86789c95462216a3167d7b98b202a5bf4c0b2
Author: Austin Seipp <austin@well-typed.com>
Date:   Fri Apr 4 10:33:03 2014 -0500

    Revert "Revert ad15c2, which causes Windows seg-faults (Trac #8834)"

    This reverts commit a79613a75c7da0d3d225850382f0f578a07113b5.