[clang] [clang-tools-extra] [clangd] show lambda name instead of operator() in signature help (PR #101857)

[Timothy Akintilo via cfe-commits]

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@@ -876,6 +876,11 @@ class Sema;
     /// function pointer or reference (C++ [over.call.object]).
     FunctionDecl *Function;
 
+    /// LambdaName - When the OverloadCandidate is for a
+    /// lambda's operator(), points to the declaration of
+    /// the lambda variable.
+    VarDecl *LambdaName{nullptr};
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tilobyte wrote:

thanks for the example!
i don't think this patch affects behavior in this scenario. the current behavior (preserved in this patch) is not to produce any signature help. i believe this is because within `bar()` it is not known that `Ls` has a call operator. unless i'm misunderstanding?
<img width="438" alt="Screenshot 2024-09-09 at 20 05 32" src="https://github.com/user-attachments/assets/f19431e0-3764-4530-8cf7-22cec4f8f228">

https://github.com/llvm/llvm-project/pull/101857