Changes to ghc

Changes to ghc:
commit 980badd133d0e8694bfe2fad7c123da0e51c3250
Author: Patrick Palka <patrick@parcs.ath.cx>
Date:   Thu Dec 5 11:19:25 2013 -0500

    Remove the LFBlackHole constructor

    After commit 55c703b8fdb0, this code is no longer used anywhere.