[Bug target/120840] CPython miscompiled with preserve_none

[hjl.tools at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120840

--- Comment #5 from H.J. Lu <hjl.tools at gmail dot com> ---
I backported the patch to GCC 15 branch, which works.  Sam, is it possible to
identify which commit on master caused the miscompilation?