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

compiler/testData/diagnostics/tests/smartCasts/inference/kt25432.fir.kt

@@ -0,0 +1,11 @@
+// !WITH_NEW_INFERENCE
+// ISSUE: KT-25432
+
+class Data<T>(val s: T)
+
+fun test(d: Data<out Any>) {
+    if (d.s is String) {
+        d.s.length
+    }
+}
+