[Bug libstdc++/101258] std ::is_integral_v is undocumented

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101258

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
It does exactly what the standard says it does. And it's self explanatory.