Add all the plumbing needed for MC to expand cfi to the old tables in

Add all the plumbing needed for MC to expand cfi to the old tables in
the final assembly. It is the same technique used when targeting
assemblers that don't support .loc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130587 91177308-0d34-0410-b5e6-96231b3b80d8