[Bug tree-optimization/109175] error: 'void* __builtin_memset(void*, int, long unsigned int)' writing 4 or more bytes into a region of size 0 overflows the destination [-Werror=stringop-overflow=]

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109175

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Reduced all the way removing all of the classes showing exactly what I thought
it was:
```
void *ao();
float *aq(long t) {
  if (t)
    return nullptr;
  return static_cast<float *>(ao());
}
float v;
void at(long t) {
  long a = sizeof(0), i = 0;
  auto b = aq(t);
  for (; i < a; ++i)
    b[i] = v;
  for (; i < t; ++i)
    b[i] = 0.0f;
}
```

Notice how there is no check for null on aq.