Bug#162612: libc6-dev: telling gcc to optimize causes C99 violations, thanks to endian.h

[Philip Blundell <pb@nexus.co.uk>]

tags 162612 + upstream
thanks

I confirmed that this still occurs with glibc 2.3.1.

BIG_ENDIAN and its friends are defined whenever libc's "4.3BSD"
featureset is enabled.  This is the default if you don't request
something else, e.g. with -D_POSIX_SOURCE.

It does seem slightly unfortunate that the default mode (and
-D_GNU_SOURCE, which is what the GNU project recommends for new code)
include this namespace pollution.  I'm not sure what the chances of
getting this changed are, but we can at least mention it to upstream.

p.