It’s not clear whether negative NaN floats are supposed to print as
"-nan" or "nan" on RISC-V (https://cplusplus.github.io/LWG/issue4101).
Until that’s resolved, don’t require that logging such a float with
Abseil produce the same result as streaming it to an ostream does.

Closes: https://github.com/abseil/abseil-cpp/issues/1684
PiperOrigin-RevId: 641942176
Change-Id: Iec7ef130cc15c114714f2d124cb37886b3c37ab4