[Bug c++/45113] absent or confusing diagnostics of invalid template argument list in implicit template class instantiation

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=45113

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Clang has a nice error for test3

45113_3.cc:2:15: error: type-id cannot have a name
typedef U<int x,int y> A;
              ^
45113_3.cc:2:21: error: type-id cannot have a name
typedef U<int x,int y> A;
                    ^
2 errors generated.