[Bug tree-optimization/119605] change the code fixup_cfg for __builtin_unreachable to be a verifier

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119605

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
I thought we verify this already ...