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

[via cfe-commits]

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@@ -272,6 +273,26 @@ QualType ObjCMessageExpr::getCallReturnType(ASTContext &Ctx) const {
   return Ctx.getReferenceQualifiedType(this);
 }
 
+std::pair<const NamedDecl *, const Attr *>
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halbi2 wrote:

It is this way in CallExpr::getUnusedResultAttr too. I would change it in both places?
Maybe is this way so that different Attrs can be supported in the future, not just WarnUnusedResultAttrs.

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