[clang] [Clang]: enhance handling of [[deprecated]] attribute diagnostics for local variables (PR #113575)

[via cfe-commits]

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@@ -424,6 +424,8 @@ Improvements to Clang's diagnostics
   name was a reserved name, which we improperly allowed to suppress the
   diagnostic.
 
+- Clang now diagnoses [[deprecated]] attribute usage on local variables (#GH90073).
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Sirraide wrote:

```suggestion
- Clang now diagnoses ``[[deprecated]]`` attribute usage on local variables (#GH90073).
```
Oh, another nit here. I only noticed this now

https://github.com/llvm/llvm-project/pull/113575