Those are cached and reused across runs, which doesn't qualify to mesa
as "static" indeed. Properly marking those as dynamic is more true, and
brings in slight performance benefits just by avoiding the resulting
(and later silenced) mesa warning.
https://bugzilla.gnome.org/show_bug.cgi?id=782344
In cogl use cogl-config.h and in clutter use clutter-build-config.h. We
can't use clutter-config.h in clutter because its already used and
installed.
https://bugzilla.gnome.org/show_bug.cgi?id=768976
