[Bug c++/120335] Defining a function return type allowed with -pedantic-errors with using statement

[eczbek.void at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120335

--- Comment #3 from eczbek.void at gmail dot com ---
This also has the same issue:
```
auto(*x)()->struct{};
```