REGISTER_BYTE() and pseudos

[Richard Earnshaw]

> Yeah, I was going to chime in, but I am behind on this thread.
> Richard, look at the sh-tdep.c file. I checked in the sh5 work.  It
> still needs another round of cleaning but ti should pretty much all be
> there.

OK, I'll have another look.  

The bit I'm worried about though is if we call something like 
generic_get_saved_register for a pseudo and we hit a call_dummy frame.  
The code in there goes:

      if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame))
        {
          if (lval)             /* found it in a CALL_DUMMY frame */
            *lval = not_lval;
          if (raw_buffer)
            memcpy (raw_buffer,
                    generic_find_dummy_frame (frame->pc, frame->frame) +
                    REGISTER_BYTE (regnum),
                    REGISTER_RAW_SIZE (regnum));
          return;

Which will try to look up the pseudo in the buffer even if it isn't there.