[Bug tree-optimization/93052] Wrong optimizations for pointers: `p == q ? p : q` -> `q`

[ch3root at openwall dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93052

--- Comment #4 from Alexander Cherepanov <ch3root at openwall dot com> ---
Could you please provide a bit more specific reference? If you mean various
discussions about C provenance semantics then they are not about these cases.
All examples in pr93051 and in this pr fully respect provenance -- it's the
compiler who changes the provenance. In some sense dealing with these bugs is a
prerequisite for a meaningful discussion of C provenance semantics: it's hard
to reason about possible boundaries of provenance when there are problems with
cases where provenance is definitely right.