build failure

[Roland McGrath]

> The interface is lousy.
> I suggest that INTERNAL_SYSCALL be re-architected to return an error
> indication as an output argument to the macro, i.e.
> 
>   result = INTERNAL_SYSCALL (errno, name, nr, args...) 

That is ok by me.  I considered a hairier interface to begin with.  At
first the uses of INTERNAL_SYSCALL were for a few special cases that cannot
fail and so weren't checked, so I just kept the macro interface minimal.