What seems to have happened is that your change modified the behavior of
the API used by back ends, but did not modify the back ends to
compensate for that change. I think we should get back in synch, either
by undoing your change, or by updating the back ends. I don't have a
preference as to which approach is taken, though I suspect that undoing
your change is easier, in that it probably requires auditing less code.
It would be, and I have no preference (other than that the current
definition makes no sense if you look at it). My change was originally
just going to be for apply_args_size, and does match the definition
there - I just took it across to the similar function.
I'll make either change that's necessary, let's just come to an
agreement on what it should be. I think it should be like
FUNCTION_ARG_REGNO_P.