[Bug tree-optimization/102769] wrong code at -O1 and above on x86_64-linux-gnu

[zhendong.su at inf dot ethz.ch]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102769

--- Comment #5 from Zhendong Su <zhendong.su at inf dot ethz.ch> ---
Yes, it's clear that the code is invalid. I should update my reduction script
to use more recent clang and gcc for ruling out UBs.