[Bug tree-optimization/117760] `a != b` implies that a or b is also non-zero

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117760

--- Comment #9 from Drea Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Matteo Nicoli from comment #8)
> (In reply to Drea Pinski from comment #7)
> > Note:
> > (bit_and:c (ne:c @0 @1) (ne (bit_ior @0 @1) integer_zerop))
> > 
> > The second `:c` can be removed.
> > Will fix in a little bit.
> 
> I'm going to fix that this weekend

I already fixed that in r17-231-gc65691bc5a2873e0e2ffbfcaa80eb9bdc6e1f7b8 (but
I messed up slightly when combining the ones which result in a constant;
swapped around the behavior).