[clang] [Sema] Preserve ContainsUnexpandedParameterPack in TransformLambdaExpr (PR #86265)

[Younan Zhang via cfe-commits]

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@@ -1105,6 +1107,8 @@ void Sema::ActOnLambdaExpressionAfterIntroducer(LambdaIntroducer &Intro,
 
   CXXMethodDecl *Method = CreateLambdaCallOperator(Intro.Range, Class);
   LSI->CallOperator = Method;
+  // Temporarily set the lexical declaration context to the current
+  // context, so that the Scope stack matches the lexical nesting.
   Method->setLexicalDeclContext(CurContext);
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zyn0217 wrote:

I recovered this comment from https://reviews.llvm.org/D124351 because at least it tries to explain something - better than nothing that just makes the lambda parsing dimmer. 

https://github.com/llvm/llvm-project/pull/86265