[Bug target/115966] [15 Regression] Miscompilation of 403.gcc with -Ofast -march=native on x86_64

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115966

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
I think we have a few other gcc miscompiles now (but from SPEC CPU 2017), so
this one is probably related.  Does -fno-strict-aliasing fix it?