[clang] [clang][Sema] Refine unused-member-function diagnostic message for constructors (PR #84515)

[Aaron Ballman via cfe-commits]

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@@ -76,10 +76,33 @@ struct S {
   struct SVS : public VS {
     void vm() { }
   };
+
+  struct CS {
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AaronBallman wrote:

When switching the diagnostic approach, be sure to add test coverage for unused copy/move constructors, copy/move assignment, and destructors (you can get an unused destructor if you only use `new` to allocate the class rather than stack allocate it).

https://github.com/llvm/llvm-project/pull/84515