[clang] Thread Safety Analysis: Improved pointer handling (PR #127396)

[Ilya Biryukov via cfe-commits]

================
@@ -143,6 +143,11 @@ Improvements to Clang's diagnostics
 - A statement attribute applied to a ``case`` label no longer suppresses
   'bypassing variable initialization' diagnostics (#84072).
 
+- The :doc:`ThreadSafetyAnalysis` now supports ``-Wthread-safety-pointer``
----------------
ilya-biryukov wrote:

I propose to add some caveats here. As chatted offline, the analysis does not do any alias analysis and will miss  cases like:

```cpp
struct Foo {
  std::mutex mu;
  int *p GUARDED_BY(mu);

  int* do_something() {
    mu.lock();
    int* q = p;
    mu.unlock();
    return q;
  }
};
```

This change is still very-very useful, I just want to make sure the folks don't misinterpret it as catching even more.

https://github.com/llvm/llvm-project/pull/127396