[llvm-branch-commits] [libcxx] Prepare libcxx and libcxxabi for pointer field protection. (PR #151651)

[Louis Dionne via llvm-branch-commits]

================
@@ -34,10 +34,13 @@ template <class _Tp, class = void>
 struct __libcpp_is_trivially_relocatable : is_trivially_copyable<_Tp> {};
 #endif
 
+// __trivially_relocatable on libc++'s builtin types does not currently return the right answer with PFP.
----------------
ldionne wrote:

```suggestion
// __trivially_relocatable on libc++'s builtin types does not currently return the right answer with PFP.
```

What do you mean by "libc++ builtin types"? Do you mean libc++ types like `std::string` & friends? We are currently not using Clang's notion of trivially-relocatable for anything, so I'm not certain we need to disable this when PFP is enabled. IMO we need to take a look at each individual type who advertises `__trivially_relocatable` and check whether that's fine with PFP.

https://github.com/llvm/llvm-project/pull/151651