Simplify accept4, recvmmsg, sendmmsg code

[Joseph Myers]

On Tue, 9 May 2017, Adhemerval Zanella wrote:

> > -/* Support for sendmmsg functionality was added in 3.0.  The macros
> > -   defined correspond to those for accept4 and recvmmsg.  */
> > -#define __ASSUME_SENDMMSG_SYSCALL	1
> > +/* Support for sendmmsg functionality was added in 3.0.  */
> >  #define __ASSUME_SENDMMSG	1
> 
> Since you are there, wouldn't be better to add a comment that we
> kept __ASSUME_SENDMMSG because of resolv code instead of kernel
> support?

That's not what we do for __ASSUME_SENDFILE, __ASSUME_ATFCTS etc. (other 
macros for features present for ports using the Linux kernel but not 
necessarily for other ports).

-- 
Joseph S. Myers
joseph@codesourcery.com