[Bug tree-optimization/94898] Failure to optimize compare plus sub of same operands into compare

[gabravier at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94898

--- Comment #1 from Gabriel Ravier <gabravier at gmail dot com> ---
Also, if this function is changed to return `int`, it can then be optimized to
a conditional move, which GCC fails to do