[clang] [clang-tools-extra] Reland: [clang] NFC: Clear some uses of MemberPointerType::getClass (PR #132317)

[Alexander Kornienko via cfe-commits]

alexfh wrote:

The reduced test case:
```
template <typename>
struct A;
template <typename T>
struct A<void (T::C::*)(int &, T *)> {};
template <typename T>
void e(T) {
  A<T> f;
}
struct S {
  struct C {
    void h(int &, S *);
  };
  void i() { e(&C::h); }
};
```

https://gcc.godbolt.org/z/8Pq9EWbTv

https://github.com/llvm/llvm-project/pull/132317