[Bug tree-optimization/94802] Failure to recognize identities with __builtin_clz

[gabravier at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94802

--- Comment #1 from Gabriel Ravier <gabravier at gmail dot com> ---
Also, there are also patterns like `__builtin_clz(a - b) == 31`, which can be
optimized to `(a - b) == 1`