[Bug c++/121702] [Modules] `export namespace N { using namespace M; }` does not export.

[shyeyian at petalmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121702

--- Comment #3 from shyeyian <shyeyian at petalmail dot com> ---
I'm trying to find it out in C++ standards as clang++ seems to support it
(export using namespace => export everything)