[AArch64] Storing a copy of all function arguments on the stack for debug/instrumentation?

[Philipp Tomsich]

To aid in debugging and instrumentation (we would like to look at a stopped
program and unwind while recording all argument values), I would like to
either store a copy of all register arguments on the caller's stack or
record them in the callee's stack on function entry.

Both options are straightforward to implement, but I'd like to avoid
duplicating work.
Has anyone been working on something like this?

Thanks,
Philipp.