Patch to codingconventions.html

[Hans-Peter Nilsson]

On Wed, 15 Sep 2004, Joseph S. Myers wrote:

> This patch to codingconventions.html documents a convention used in GCC
> sources which Kenner explained in
> <http://gcc.gnu.org/ml/gcc-patches/2004-01/msg00311.html> but didn't then
> document when I requested it.  OK to commit?

??? is for something not really investigated, a hunch or
possible problem, maybe just seen by browsing the code.  FIXME
is for a deficiency or shortcoming that's a little bit more
defined, but maybe just as a problem.  TODO describes a way to
fix the FIXME (had it been one, if you know what I mean).  At
least that's what they mean to me.

brgds, H-P