[clang] [Clang] Implement CWG3005 Function parameters should never be name-independent (PR #138245)

[Erich Keane via cfe-commits]

https://github.com/erichkeane commented:

THIS example should also be ill-formed by CWG3005:

```

struct S3 {
   union {
     int _;
     };
    int _; // error, the one in the union isn't type independent
};
```

https://github.com/llvm/llvm-project/pull/138245