[Bug c++/120635] Support something like [[clang::no_specializations]] attribute

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120635

--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
As PR126254 mentions, for type_order too (#c0 mentions that with a maybe).