[clang] [Clang][analyzer] replace Stmt* with ConstCFGElementRef in SymbolConjured (PR #128251)

[Fangyi Zhou via cfe-commits]

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@@ -645,6 +645,7 @@ struct StreamOperationEvaluator {
   SymbolRef StreamSym = nullptr;
   const StreamState *SS = nullptr;
   const CallExpr *CE = nullptr;
+  std::optional<CFGBlock::ConstCFGElementRef> ElemRef;
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fangyi-zhou wrote:

I'm not entirely sure whether I get your point correctly. This value needs to be stored when `Init` is called, and used in other calls (e.g. `bindReturnValue`). The reason why this is declared as an optional is that there is no default constructor for `ConstCFGElementRef`, so I used an optional to give an absent value (I guess it could have been a pointer like other ones)

https://github.com/llvm/llvm-project/pull/128251