[clang-tools-extra] [clang-tidy] Add modernize-use-to-underlying check (PR #210459)

[Yanzuo Liu via cfe-commits]

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@@ -0,0 +1,163 @@
+//===--- UseToUnderlyingCheck.cpp - clang-tidy ----------------------------===//
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zwuis wrote:

```suggestion
//===----------------------------------------------------------------------===//
```

https://llvm.org/docs/CodingStandards.html#file-headers

https://github.com/llvm/llvm-project/pull/210459