[PATCH] [x32] Add X32 backend

[Derek Schuff]

This patch is fine (in my opinion) to commit, but before we get too far into landing more stuff, I would really like to see a sort of roadmap, e.g. what are the major data structures what will need to be changed, etc. Even if it's just a raw patch dump somewhere.

Also I might be interested in trying this out myself, what would I need to be able to do that? Just a distro with x32 libs?

http://reviews.llvm.org/D4181