[clang-tools-extra] [clang-tidy][NFC] Don't store a redundant copy of `HeaderFileExtensions` in every check (PR #190302)

[Baranov Victor via cfe-commits]

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@@ -480,6 +480,16 @@ class ClangTidyCheck : public ast_matchers::MatchFinder::MatchCallback {
     ClangTidyContext *Context;
   };
 
+  /// Returns the list of header file extensions from the context.
+  const FileExtensionsSet &getHeaderFileExtensions() const {
+    return Context->getHeaderFileExtensions();
+  }
+
+  /// Returns the list of implementation file extensions from the context.
+  const FileExtensionsSet &getImplementationFileExtensions() const {
+    return Context->getImplementationFileExtensions();
+  }
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vbvictor wrote:

I don't see:)

https://github.com/llvm/llvm-project/pull/190302