[clang] [LifetimeSafety] Revamp how accesses and uses are handled (PR #225799)

[Utkarsh Saxena via cfe-commits]

https://github.com/usx95 approved this pull request.

This change makes sense to me.

Double checking that this is orthogonal the large #false positive in invalidations:
```cpp
void foo(std::vector<int>* p) {
    p->push_back(42);
    p->push_back(43);  // use-after-invalidation!
    // because push_back takes in `p` as implicit this which is still an access.
}
```
https://godbolt.org/z/7Gfs7xeeY

https://github.com/llvm/llvm-project/pull/225799