[Bug tree-optimization/118650] `(even + unknown) & 1` is not optimized to just `unknown & 1` at gimple level

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118650

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
maybe also a thing for SSA backprop?  Eliminating ops that only affect bits
masked by &?  Or ops that only affect bits added by |?