[llvm] [ARMISelDAGToDAG] use MO_FrameIndex to represent FrameIndex rather than MO_Register for INLINEASM (PR #69654)

[Eli Friedman via llvm-commits]

efriedma-quic wrote:

> Is that possible to know (the current stack depth) during SelectionDAGISel? Or should that be handled elsewhere later?

You can sort of tell some things; for example, I think we track whether the function has dynamic allocation.  But the stack layout isn't finalized until FrameLowering.

https://github.com/llvm/llvm-project/pull/69654