Warning for trigraphs in comment?

[Zack Weinberg]

Gabriel Dos Reis <gdr@integrable-solutions.net> writes:

>    Second, consider the comment line.  Did you notice that it ends oddly,
>    with a "/"?
>
>        // What will the next line do? Increment???????????/
>                                                           ^
...
>
> is extracted from Herb's GTW #86 -- full message appended below.
> I would suggest we warn for trigraphs in comments.

This was discussed a couple weeks back.  3.4 now warns about ??/\n in
a comment.  The change is self-contained and could be put into 3.3.1
if people think that's a good idea.

zw