[Bug libstdc++/100017] [11/12 regression] error: 'fenv_t' has not been declared in '::' -- canadian compilation fails

[unlvsur at live dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100017

--- Comment #50 from cqwrteur <unlvsur at live dot com> ---
Backported GCC 11 patch
https://gcc.gnu.org/pipermail/gcc-patches/2021-December/587255.html