test: add acceptance test 86

fix: prevent mutual recursion for expect type code gen functions

examples/acceptance_tests/086/validators/other.ak

@@ -0,0 +1,21 @@
+use aiken/transaction.{ScriptContext}
+use aiken/transaction/credential.{Address}
+
+type TestData {
+  addr: Address,
+}
+
+type TestDatum {
+  data: Option<TestData>,
+}
+
+validator {
+  fn validate(raw_datum: Data, _redeemer: Data, _context: ScriptContext) -> Bool {
+    expect datum: TestDatum = raw_datum
+    let TestDatum { data } = datum
+    when data is {
+      Some(_) -> True
+      None -> False
+    }
+  }
+}