[clang-tools-extra] Add check 'modernize-use-enum-class' (PR #138282)

[Baranov Victor via cfe-commits]

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@@ -0,0 +1,13 @@
+// RUN: %check_clang_tidy -std=c++11-or-later %s cppcoreguidelines-use-enum-class %t -- -config="{CheckOptions: {cppcoreguidelines-use-enum-class.IgnoreUnscopedEnumsInClasses: true}}" --
+
+enum E {};
+// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: enum 'E' is unscoped, use 'enum class' instead [cppcoreguidelines-use-enum-class]
+
+enum class EC {};
+
+struct S {
+  enum E {};
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vbvictor wrote:

Please add test with forward decl.

https://github.com/llvm/llvm-project/pull/138282