[FIR-TEST] Add new testdata generated after changes in previous commit

compiler/testData/diagnostics/tests/controlStructures/kt30406.fir.kt

@@ -0,0 +1,16 @@
+// !LANGUAGE: +NewInference
+// !DIAGNOSTICS: -UNUSED_EXPRESSION
+// !CHECK_TYPE
+// Issue: KT-30406
+
+interface Option<out T> {
+    val s: String
+}
+class Some<T>(override val s: String) : Option<T>
+class None(override val s: String = "None") : Option<Int>
+
+fun test(a: Int): Option<Any> =
+    if (a == 239)
+        Some("239")
+    else
+        None()