[Bug tree-optimization/90610] [10 Regression] 526.blender_r miscompared on znver1 with -Ofast -march=native since r271463

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90610

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
It's actually cunroll that exposes the issue in zbufclip.  Ah, oops.