Wenum-promotion (PR7651 Define -Wextra strictly in terms of other warning flags)

[Gabriel Dos Reis]

"Manuel López-Ibáñez" <lopezibanez@gmail.com> writes:

| :ADDPATCH c++:
| 
| This patch continues the effort to fix PR7651 [1].
| 
| A new option -Wenum-promotion takes over the warning for an enumerator
| and a non-enumerator appearing in a conditional expression.

I would like to see this case instead covered by the conversion/coercion
warning switch.  

Yes, I know you're trying to preserve existing practice; but we have
to keep in the fore that the current situation is not the result of
systematic principles, and now is a good to time to rationalize all
that (and thanks for your contribution in this area!).

-- Gaby