[Bug c++/108223] GCC rejects QNaN in __builtin_fmax constant expression

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108223

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
That being said this works:
#include <cmath>
constexpr bool test() {
  auto val = std::max(__builtin_nan(""), __builtin_nan(""));

  return true;
}

static_assert(test());