[LifetimeSafety] UAFs via pointer-to-pointer and reference-to-pointer dereferencing are not diagnosed

https://godbolt.org/z/ezK5zbq48

`-Werror=experimental-lifetime-safety -Werror=experimental-lifetime-safety-cross-tu-suggestions -Wexperimental-lifetime-safety-intra-tu-suggestions -Xclang -fexperimental-lifetime-safety -Xclang -fexperimental-lifetime-safety-inference -std=c++20 -fsanitize=address,undefined`

```cpp
int main() {
int *p{};
int *&pp{p};
{
int a = 42;
p = &a;
}
auto result = *pp;
}
```

Might be related to https://github.com/llvm/llvm-project/pull/168344