Test refactoring

compiler/testData/diagnostics/tests/smartCasts/publicVals/customGetter.kt

@@ -0,0 +1,13 @@
+public class X {
+    private val x : String? = null
+    public val y: CharSequence?
+        get() = x?.subSequence(0, 1)
+    public fun fn(): Int {
+        if (y != null)
+            // With non-default getter smartcast is not possible
+            return y<!UNSAFE_CALL!>.<!>length() 
+        else
+            return 0
+    }
+}
+