a warning to implement

[Robert Dewar]

<<I've only proposed it as a feature.  I don't think this is
documented as such.
>>

So no one could actually be using 

int a = a;

for any useful purpose right now as I understand it, so I am at a complete
loss to understand Gaby's claim that some people think this is useful.
I could see how some people might be able to give it a useful meaning
(but I object in principle to encouraging people to write undefined C
counting on it to have peculiar meanings in compiler), but Gaby claimed
that some people think it is useful now, and I just can't understand that.