[Bug tree-optimization/81162] [8 Regression] UBSAN switch triggers incorrect optimization

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81162

--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
-fsanitize=integer-divide-by-zero is what seems to trigger this.