[klibc] Register parameters are unsafe with gcc 3.3.2

[H. Peter Anvin]

H. Peter Anvin wrote:
> Alexander E. Patrakov wrote:
> 
>>
>> Other shell redirections don't work either. When I comment out the 
>> following line in klibc/klibc/arch/i386/MCONFIG:
>>
>> # REGPARM_OPT := -mregparm=3 -DREGPARM
>>
>> and rebuild klibc, everything works. Please take some action against 
>> this error, e.g. update the README file.
>>
> 
> It's not a gcc problem, it seems to be a bug in the klibc open() 
> function.  open() is a problematic function since it's technically 
> defined as being varadic, and with regparm varadic and non-varadic 
> functions have calling conventions.
> 
> Thus, it's either a klibc or an ash problem, so it's in my court.  I'll 
> take care of it.
> 

OK, sprinkling #include <unistd.h> across the ash directory did it.

If noone objecs, I'm also going to add the open() prototype to 
<fcntl.h>, since even old-style code included <fcntl.h> when using open().

Anyone would be brave enough to convert ash to prototype format?  That 
way we could use standard gcc warnings to warn for missing prototypes.

	-hpa