[clang] [clang] Diagnose [[nodiscard]] return types in Objective-C++ (PR #142541)

[Nikita Popov via cfe-commits]

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@@ -16,6 +16,7 @@
 #include "clang/AST/APNumericStorage.h"
 #include "clang/AST/APValue.h"
 #include "clang/AST/ASTVector.h"
+#include "clang/AST/Attr.h"
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nikic wrote:

Can you forward-declare WarnUnusedResultAttr instead?

https://github.com/llvm/llvm-project/pull/142541