[Bug c/90167] invalid example in GCC documentation wrt. effective type rules

[lersek at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90167

--- Comment #4 from Laszlo Ersek (RH) <lersek at redhat dot com> ---
So one way to define the behavior for the original example (from the gcc docs)
would be:

int f(void) {
  double d = 3.0;
  union a_union u = *(union a_union *)&d;

  return u.i;
}

Thanks.