This requires a knowledge of the stack size which is not known until
the frame is complete, hence the need for the XCoreFTAOElim pass
which lowers the XCoreISD::FRAME_TO_ARGS_OFFSET instrution into its
final form.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198614 91177308-0d34-0410-b5e6-96231b3b80d8