[clang-tools-extra] [include-cleaner] Report refs for enum constants used through namespace aliases (PR #106706)

[Ilya Biryukov via cfe-commits]

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@@ -534,6 +534,8 @@ TEST(WalkAST, Enums) {
   testWalk(R"(namespace ns { enum E { A = 42 }; }
               struct S { using ns::E::A; };)",
            "int e = S::^A;");
+  testWalk(R"(namespace ns { enum E { $explicit^A = 42 }; })",
+           "namespace z = ns; int e = z::^A;");
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ilya-biryukov wrote:

Could you add a test for the global specifier too?
```::A``` has a slightly different representation as `NestedNameSpecifier`, so we might want to make sure this case is also tested. (I **think** the existing code should work just fine, though).

https://github.com/llvm/llvm-project/pull/106706