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

compiler/testData/diagnostics/tests/smartCasts/openInSealed.fir.kt

@@ -0,0 +1,8 @@
+sealed class My(open val x: Int?) {
+    init {
+        if (x != null) {
+            // Should be error: property is open
+            x.hashCode()
+        }
+    }
+}