Revert "Liveness Analysis Pass"

This reverts commit r197254.

This was an accidental merge of Juergen's patch. It will be checked in
shortly, but wasn't meant to go in quite yet.

Conflicts:
	include/llvm/CodeGen/StackMaps.h
	lib/CodeGen/StackMaps.cpp
	test/CodeGen/X86/stackmap-liveness.ll