K&R and ISO

[Roland McGrath]

I don't see a problem for libc itself, as long as you make sure that it
still works to use gcc to compile K&R code with libc.  That is,
unconditionally using prototype declarations shouldn't be a problem.  Using
const instead of __const, et al, might be a problem for some old programs;
and I don't think it is worthwhile to break those without gleaning a real
benefit.  In the case of the new reserved words, we can just use __const et
al as now and let gcc's lexer rather than the preprocessor deal with them;
it already handles the __ified names for the new reserved words.

The problematic question is for the various pieces of libc that are also
used in other packages.  You should ask gnu-prog about the needs there.
I would be inclined to leave all those (glob, fnmatch, etc) as they are.