Clang accepts invalid program involving multiple inherited type members

The following invalid program is accepted by clang but rejected by gcc and others. [Demo](https://godbolt.org/z/qsco3fq5c)
```
template concept Concept = requires {typename T::marker;};
#define INJECT_MARKER using marker = int;
struct Base1{
INJECT_MARKER
};
struct Base2{
INJECT_MARKER
};

struct Derived: Base1, Base2{};

static_assert(Concept);
```