[Bug c++/96526] New built-in needed to implement std::strong_order total order on floating point types

[joseph at codesourcery dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96526

--- Comment #1 from joseph at codesourcery dot com <joseph at codesourcery dot com> ---
You could define __builtin_totalorder functions, but watch out for the 
change made to totalorder functions following a TS 18661-1 clarification 
request, from floating-point argument types to pointer argument types (so 
you'd need to handle all the cases of libm not having the functions, libm 
having them with the old prototypes as in glibc 2.25 through 2.30, libm 
having them with the new prototypes as in glibc 2.31 and later).