[K/N][Tests] Adjust moved codegen tests to new infra

^KT-61259

native/native.tests/testData/codegen/devirtualization/anonymousObject.kt

@@ -3,13 +3,17 @@
  * that can be found in the LICENSE file.
  */
 
+import kotlin.test.*
+
+val sb = StringBuilder()
+
 interface I {
     fun foo()
 }
 
 fun test() {
     val impl = object : I {
-        override fun foo() { println("zzz") }
+        override fun foo() { sb.append("zzz") }
     }
 
     val delegating = object: I by impl { }
@@ -17,6 +21,9 @@ fun test() {
     delegating.foo()
 }
 
-fun main() {
+fun box(): String {
     test()
+    assertEquals("zzz", sb.toString())
+
+    return "OK"
 }