[clang] [Clang] skip warnings for constructors marked with the [[noreturn]] attribute (PR #115558)

[via cfe-commits]

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@@ -555,6 +555,8 @@ Improvements to Clang's diagnostics
       getS(); // Now diagnoses "Reason 2", previously diagnoses "Reason 1"
     }
 
+- Clang now omits warnings for constructors marked with the ``[[noreturn]]`` attribute (#GH63009).
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Sirraide wrote:

```suggestion
- Clang now correctly recognises code after a call to a ``[[noreturn]]`` constructor
  as unreachable (#GH63009).
```
I think that’s a bit clearer; the original release note makes it sound like we stop warning about `noreturn` altogether.

https://github.com/llvm/llvm-project/pull/115558