[Bug c++/66350] typename should be forbidden in inhering constructors

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66350

--- Comment #3 from Martin Sebor <msebor at gcc dot gnu.org> ---
You're right.  My Clang test case wasn't quite the same.  Recent trunk does
fail to compile it.