[Bug libstdc++/107815] 20_util/to_chars/float128_c++23.cc FAILs

["jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107815

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Can you please uncomment the
//    std::cout << i << ' ' << std::string_view (str1, ptr1) << '\n';
and
//    std::cout << i << ' ' << std::string_view (str1, ptr5) << '\n';
lines in the test, so that it is clear at least which test it is on?
If line 66 fails, it is a fixed printing test trying to verify
that the string created by line 60 was actually the minimal.
On SPARC Solaris, I assume long double is IEEE quad, and it is the shortest
version, so should use ryu library for both cases.
Line 74 failure is about whether the created string can be read back,
in that case for IEEE quad fast_float library can't be used and so it should
use newlocale/uselocale/strtold/uselocale/freelocale, or if the OS doesn't
support newlocale/uselocale/freelocale most likely just strtod with lost
precision (so in that case the test would fail) on line 74.