test for obsolete KT-889

compiler/testData/codegen/regressions/kt889.jet

@@ -0,0 +1,9 @@
+fun Int.plus(s: String) : String {
+  System.out?.println("Int.plus(s: String) called")
+  return s
+}
+
+fun box() : String {
+   val s = "${1 + "a"}"
+   return if(s == "a") "OK" else "fail"
+}

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

@@ -64,4 +64,8 @@ public class StringsTest extends CodegenTestCase {
     public void testKt894() throws Exception {
         blackBoxFile("regressions/kt894.jet");
     }
+
+    public void testKt889() throws Exception {
+        blackBoxFile("regressions/kt889.jet");
+    }
 }