[Bug c++/100687] [modules, concepts] imported concept gives different result

[johelegp at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100687

--- Comment #2 from Johel Ernesto Guerrero Peña <johelegp at gmail dot com> ---
Another use case (Clang: https://godbolt.org/z/hTPsPbEhe) (GCC:
https://godbolt.org/z/96MqTvrKv):

`mod.cpp`:
```C++
export module mod;
export template<class T, class U>
inline constexpr bool is_same_v = false;
export template<class T>
inline constexpr bool is_same_v<T, T> = true;
```

`test.cpp`:
```C++
import mod;
static_assert(is_same_v<int, int>);
int main() {
}
```

Output:
```
test.cpp:2:15: error: static assertion failed
    2 | static_assert(is_same_v<int, int>);
      |               ^~~~~~~~~~~~~~~~~~~
```