Revert "[cxx-interop] Avoid cycles in ClangTypeExplicitSafety requests"

This reverts commit d0bad4c.

Author: j-hui

lib/ClangImporter/ClangImporter.cpp

@@ -8844,13 +8844,11 @@ CustomRefCountingOperationResult CustomRefCountingOperation::evaluate(
 
 /// Check whether the given Clang type involves an unsafe type.
 static bool hasUnsafeType(Evaluator &evaluator, clang::QualType clangType) {
-  auto req = ClangTypeExplicitSafety({clangType});
-  if (evaluator.hasActiveRequest(req))
-    // If there is a cycle in a type, assume ExplicitSafety is Unspecified,
-    // i.e., not unsafe:
-    return false;
-  return evaluateOrDefault(evaluator, req, ExplicitSafety::Unspecified) ==
-         ExplicitSafety::Unsafe;
+
+  auto safety =
+      evaluateOrDefault(evaluator, ClangTypeExplicitSafety({clangType}),
+                        ExplicitSafety::Unspecified);
+  return safety == ExplicitSafety::Unsafe;
 }
 
 ExplicitSafety