compiler standards (and/or min gcc version) supported with installed headers ?

[Roland McGrath]

> On Wed, 9 Jan 2013, Roland McGrath wrote:
> 
> > Yeah.  OK, I relent.  C89 plus 'long long' is an acceptable baseline.
> 
> In that case, is the patch removing __GNUC__ conditionals on uses of "long 
> long" OK?

> > Note that this doesn't remove the need to use __extension__ everywhere
> > on 'long long' uses.
> 
> (There are quite a few in miscellaneous places that need __extension__ 
> added, e.g. sysdeps/unix/sysv/linux/x86/sys/procfs.h.)

Perhaps someone would like to work on a test that verifies that every
header can be #include'd in a variety of -std= and feature-test macro
permutations.