[clang] [Clang] Account for the template depth of generic lambdas in default template arguments (PR #222541)

[Akash Manna via cfe-commits]

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@@ -16304,11 +16308,13 @@ TreeTransform<Derived>::TransformLambdaExpr(LambdaExpr *E) {
   // (A ClassTemplateSpecializationDecl is always a dependent context.)
   while (DC->isRequiresExprBody() || isa<CXXExpansionStmtDecl>(DC))
     DC = DC->getParent();
-  if ((getSema().isUnevaluatedContext() ||
-       getSema().isConstantEvaluatedContext()) &&
-      !(dyn_cast_or_null<CXXRecordDecl>(DC->getParent()) &&
-        cast<CXXRecordDecl>(DC->getParent())->isGenericLambda()) &&
-      (DC->isFileContext() || !DC->getParent()->isDependentContext()))
+  if (getDerived().IsLambdaAlwaysDependent())
+    DependencyKind = CXXRecordDecl::LDK_AlwaysDependent;
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akash-manna-sky wrote:

Right,
I’ve fixed by preserving the correct template-argument levels through deduction and instantiation, including for generic lambda specializations and their constraints.  I’ve added it to the test. I also updated the title and description.

https://github.com/llvm/llvm-project/pull/222541