[Bug c++/83749] Types with different language linkage are treated as equivalent types

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83749

--- Comment #1 from Marc Glisse <glisse at gcc dot gnu.org> ---
See PR2316. Don't hold your breath for a change, it is more likely that the
standard will eventually be changed to allow the current behavior.