[Bug sanitizer/85774] Incorrect stack-use-after-scope caused by missing cleanup of shadow bytes

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85774

--- Comment #4 from Martin Liška <marxin at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #3)
> Can we say in sanopt look for variables only referenced in these
> poison/unpoison ifns and not by anything else and just drop those ifns?

That's actually what happens, we remove all IFNs for these variables. But then
their stack slot is poisoned (by another VAR_DECL shading a slot) and we don't
do a clean-up in function epilogue.