Remove _BSD_SOURCE and _SVID_SOURCE

[Joseph S. Myers]

On Wed, 18 Dec 2013, Andreas Schwab wrote:

> "Joseph S. Myers" <joseph@codesourcery.com> writes:
> 
> >  This bit is only available on BSD systems (and those derived from
> > -them).  Therefore one has to use the @code{_BSD_SOURCE} feature select
> > -macro to get the definition (@pxref{Feature Test Macros}).
> > +them).  Therefore one has to use the @code{_GNU_SOURCE} feature select
> > +macro, or not define any feature test macros, to get the definition
> > +(@pxref{Feature Test Macros}).
> 
> This looks a bit strange.  First it says it's only available on BSD, but
> then it's defined by default anyway.

"on BSD systems (and those derived from them)" is a description of the 
systems, not necessarily glibc-based, supporting a feature.  The 
description of feature test macros could always be removed in such cases 
where a symbol is available by default, but that may not be the most 
helpful thing given that if someone e.g. uses _POSIX_C_SOURCE they'll find 
such symbols no longer available.

-- 
Joseph S. Myers
joseph@codesourcery.com