[clang] [llvm] [clang] Use separator for large numeric values in overflow diagnostic (PR #80939)

[Aaron Ballman via cfe-commits]

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@@ -175,6 +175,9 @@ Improvements to Clang's diagnostics
 - The ``-Wshorten-64-to-32`` diagnostic is now grouped under ``-Wimplicit-int-conversion`` instead
    of ``-Wconversion``. Fixes `#69444 <https://github.com/llvm/llvm-project/issues/69444>`_.
 
+- Clang now uses thousand separators when printing large numbers in integer overflow diagnostics.
+  Fixes `#80939 <https://github.com/llvm/llvm-project/issues/80939>`_.
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AaronBallman wrote:

```suggestion
  Fixes #GH80939.
```
We just landed a change this morning to automagically expand GitHub issue numbers, so this isn't a functional change.

https://github.com/llvm/llvm-project/pull/80939