Lay some groundwork for converting to MC-based asm printer. This is the first
of probably many patches to bring the back-end back up-to-date with all of the
recent MC changes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140697 91177308-0d34-0410-b5e6-96231b3b80d8