[Bug c++/65336] name lookup finds operator in unnamed namespace

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65336

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Thibaut LUTZ from comment #0)
> This might be a duplicate of 51577.

Yes, I think so.