[clang] [clang][ASTImporter] support import return with UnaryTransformType (PR #101517)

[Matheus Izvekov via cfe-commits]

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@@ -3636,6 +3636,10 @@ class IsTypeDeclaredInsideVisitor
     return {};
   }
 
+  std::optional<bool> VisitUnaryTransformType(const UnaryTransformType *T) {
+    return CheckType(T->getBaseType());
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mizvekov wrote:

Strictly speaking, you only need to visit the base type if the `UnaryTransformType` is not sugared, which currently is the same as being dependent.

Otherwise previous CheckType should have already stepped through it.

https://github.com/llvm/llvm-project/pull/101517