That was fixed in LLVM 3.6 in a more general way, by one of my coworkers, Ben. http://reviews.llvm.org/D6454
The prologue support directly subsumes previous behavior (the `prefix` form) and is more flexible, and with it, GHC doesn't have to rely on shuffling assembly output in order to achieve TNTC.
...There is one major issue remaining with the LLVM backend that I currently know of, its inability to implement a optimisation used by GHC called 'TABLES_NEXT_TO_CODE' (TNTC)...