[clang] [Clang] Defaults `-Wunicode-whitespace` to an error. (PR #210945)

[Aaron Ballman via cfe-commits]

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@@ -46,6 +46,11 @@ latest release, please see the [Clang Web Site](https://clang.llvm.org) or the
 
 ### C/C++ Language Potentially Breaking Changes
 
+- `-Wunicode-whitespace` now defaults to an error.
+The previous behavior can be restored with `-Wno-error=unicode-whitespace`.
+Clang will stop accepting non-ascii whitespaces as token seperator
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AaronBallman wrote:

```suggestion
Clang will stop accepting non-ascii whitespaces as token separators
```

https://github.com/llvm/llvm-project/pull/210945