[clang] Fix cycle in importing template specialization on auto type with typename (PR #162514)

[Shafik Yaghmour via cfe-commits]

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@@ -254,6 +254,7 @@ class TypeSourceInfo;
     /// Declaration (from, to) pairs that are known not to be equivalent
     /// (which we have already complained about).
     NonEquivalentDeclSet NonEquivalentDecls;
+    llvm::DenseSet<const Decl *> DeclTypeCycles;
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shafik wrote:

Please add a description of this member like all the others above.

https://github.com/llvm/llvm-project/pull/162514