value range propagation for _bitwise_ OR

[Ali Çehreli]

Jérôme M. Berger wrote:
> Steven Schveighoffer wrote:
>> Fails for test case:
>>
>> minA = 4, maxA = 4, minB = 4, maxB = 6 (outputs 7, accurate result is 6).
>>
> 	Nope, outputs 6. Note that I've run an exhaustive search for all
> combinations in the [0, 63] range, so if there are mistakes they
> have to be outside that range...
> 
> 		Jerome

I confirm. Jerome's code passes my randomized test.

Ali