[Bug c++/86747] [8/9 Regression] rejects-valid with redundant friend declaration

[aoliva at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86747

--- Comment #5 from Alexandre Oliva <aoliva at gcc dot gnu.org> ---
https://gcc.gnu.org/ml/gcc-patches/2018-11/msg01546.html