KT-725 test for obsolete issue

compiler/testData/codegen/regressions/kt725.kt

@@ -0,0 +1,8 @@
+fun Int?.inc() = this.sure().inc()
+
+public fun box() : String {
+    var i : Int? = 10
+    val j = i++
+
+    return if(j==10 && 11 == i) "OK" else "fail"
+}

compiler/tests/org/jetbrains/jet/codegen/ClassGenTest.java

@@ -289,4 +289,8 @@ public class ClassGenTest extends CodegenTestCase {
     public void testKt723() throws Exception {
         blackBoxFile("regressions/kt723.kt");
     }
+
+    public void testKt725() throws Exception {
+        blackBoxFile("regressions/kt725.kt");
+    }
 }