[clang-tools-extra] clang tidy: add header ignore option to include duplicate files (PR #167046)

[Baranov Victor via cfe-commits]

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@@ -0,0 +1,2 @@
+// dummy other.h (should warn on duplicate includes)
+#pragma once
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vbvictor wrote:

add neline

https://github.com/llvm/llvm-project/pull/167046