Changes to ghc(4)

Changes to ghc:
commit ad0b943293cce74baf06ea36e1a4d51a3631dfdf
Author: Simon Marlow <marlowsd@gmail.com>
Date:   Thu Nov 14 09:13:51 2013 +0000

    Fix some cases where we were leaving slop in the heap (#8515, #8298)

commit 5b0b83becfb14d1eeffd38887ad66ee81a1c48b5
Author: Simon Marlow <marlowsd@gmail.com>
Date:   Wed Nov 13 14:48:51 2013 +0000

    simplify processNurseryForDead

    It wasn't actually broken, but it wasn't obviously right either.

commit 35c05d71cb84c25983ab19b1010ac93ab040b266
Author: Simon Marlow <marlowsd@gmail.com>
Date:   Wed Nov 13 14:45:45 2013 +0000

    comments

commit 334545e010051f31266f6637fa999d1df438b065
Author: Simon Marlow <marlowsd@gmail.com>
Date:   Wed Nov 13 10:21:47 2013 +0000

    fix a small memory leak with +RTS -hb