[Bug c/123987] isinfl isinff incorrectly for x86 and arm64

[ubizjak at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123987

--- Comment #1 from Uroš Bizjak <ubizjak at gmail dot com> ---
https://cppreference.com/w/c/numeric/math/isinf.html

Return value:
Nonzero integral value if arg has an infinite value, ​0​ otherwise.