[Bug c++/115222] clang does not think libstdc++'s std::optional is nothrow destructible

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115222

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
here is a much reduced testcase:
```
struct A {
  ~A() noexcept(false);
};
union _Storage {
    A _M_value;
    ~_Storage();
};
static_assert(noexcept(_Storage{}));
```