RFA: make sim interface use gdbarch methods for collect/supply

[Jim Blandy]

Daniel Jacobowitz <drow@false.org> writes:
> GDB won't have to know where to place their contents in the buffer!
> That's the point of using a regset.  You convert the 'g' packet output
> to a binary blob in the obvious way, and then that's your regset.  The
> target architecture supplies a regset that expects the format provided
> by the 'g' packet.  Is there some problem with that plan?

No, regsets are perfect for 'g'.  I was thinking of the single-
register case (all under the assumption that we'd like to restrict
uses of supply_register and collect_register to regset functions).
What do you do with, say, the individual registers from your fancy 'T'
reply?

As far as I can tell, regsets don't serve this case well, which makes
them (in their current state) less than suitable as a universal
register transfer interface.