[clang] [clang] Emit bad shift warnings (PR #70307)

[Aaron Ballman via cfe-commits]

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@@ -686,6 +686,8 @@ Improvements to Clang's diagnostics
 - Clang no longer emits a "no previous prototype" warning for Win32 entry points under ``-Wmissing-prototypes``.
   Fixes #GH94366.
 
+- Clang now diagnoses non-C++11 integer constant expressions. Fixes #GH59863
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AaronBallman wrote:

```suggestion
- Clang now diagnoses integer constant expressions that are folded to a constant value as an extension in more circumstances . Fixes #GH59863
```

https://github.com/llvm/llvm-project/pull/70307