Use GCC's -Wlogical-op if possible

[Gerald Pfeifer]

On Tue, 23 Jun 2009, Paul Vriens wrote:
>> For those interested, here's the make log in Monday's git. 94 warnings 
>> for me.
> Sent 3 patches based on your log.
> 
> I have less (55) warnings on 4.3.2 btw, but most look like false positives.

On my FreeBSD test system I am see no warnings triggered by -Wlogical-op
any more.  How does it look on your side?

Depending on your findings, we may want to enable -Wlogical-op by default
and I'd submit a patch to that end.

Gerald