Get rid of some warnings

[Alan Modra]

On Sat, Jun 23, 2001 at 11:12:08AM +0200, Andreas Jaeger wrote:
> 	* disassemble.c (disassembler_usage): Add unused attribute.
> 
> 	* unwind-ia64.c (unw_decode_x1): Add unused attribute for
> 	parameter 'code'.
> 	(unw_decode_x2): Likewise.
> 	(unw_decode_x3): Likewise.
> 	(unw_decode_x4): Likewise.

OK.