[clang] Delete dead value dependence check. (PR #211706)

[Eli Friedman via cfe-commits]

efriedma-quic wrote:

I can technically write testcases that are affected by this patch:

```
template<int x> struct A {
  static const int xx = 0;
  void f(decltype(*(int(*)[xx])0));
  void f(decltype(*(int(*)[*&xx])0));
};
```

That said, I can't come up with any way to cause a practical issue.

https://github.com/llvm/llvm-project/pull/211706