[Bug libstdc++/104772] std::numeric_limits<__float128> should be specialized

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104772

--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
And the reason for the helper functions is C++11 which would not like
temporaries in constexpr functions.