[Bug c++/117993] [15 regression] inherited variables and functions not found in nested class

[sjames at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117993

--- Comment #1 from Sam James <sjames at gcc dot gnu.org> ---
Clang 19 accepts it. Notably, Clang 19 has a similar template instantiation
lookup change like GCC 15 does.