[Bug c/53182] GNU C: attributes without underscores should be discouraged / no longer be documented e.g. as examples

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53182

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to sandra from comment #3)
> I also think there are other compilers that have
> copied the GCC attribute syntax; do they also recognize both the underscore
> and non-underscore name variants?

Yes (confirmed for Clang and Intel, I don't know about others).