[Bug tree-optimization/124618] aggressive-loop-optimizations false positive UB warning

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124618

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The problem is dealing with std::launder. 


Add a simple help in data to say that >8 for size before the launder gets rid
of the warning. That is:
```
  int* data() noexcept
  {
    if (size_ > 8) __builtin_unreachable();
    return std::launder(reinterpret_cast<int*>(storage_));
  }
```

This should help code in general anyways ...