[Bug tree-optimization/116026] Copying or moving a std::variant that can be a vector causes a maybe-uninitialized warning with -fsanitize=address -Og -finline-functions-called-once

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116026

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
```
  MEM[(struct _Variant_storage *)&b]._M_index = 1;
  .ASAN_MARK (UNPOISON, &D.32835, 1);
  .ASAN_MARK (UNPOISON, &D.32841, 1);
  .ASAN_MARK (POISON, &D.32841, 1);
  _27 = &b.D.31055.D.30629.D.30544.D.30409.D.30292.D.30193._M_index;
  .ASAN_CHECK (6, _27, 1, 8);
  _28 = b.D.31055.D.30629.D.30544.D.30409.D.30292.D.30193._M_index;
```

_28 is not being optimized to 1 so then GCC warns on unreachable code.

I forgot at -Og, there is a limited optimization happening.