[Bug c++/125714] [C++20] ignored pure attribute on constexpr destructor breaks constant-evaluation deallocation tracking

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125714

--- Comment #2 from Drea Pinski <pinskia at gcc dot gnu.org> ---
The documentation just says:
Because a pure function cannot have any observable side effects it does not
make sense for such a function to return void. Declaring such a function is
diagnosed.

But it does not say it has to mean anything and not ignored ....