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

^KT-61259

native/native.tests/testData/codegen/boxing/boxing9.kt

@@ -3,13 +3,13 @@
  * that can be found in the LICENSE file.
  */
 
-package codegen.boxing.boxing9
-
 import kotlin.test.*
 
+val sb = StringBuilder()
+
 fun foo(vararg args: Any?) {
     for (arg in args) {
-        println(arg.toString())
+        sb.appendLine(arg.toString())
     }
 }
 
@@ -17,6 +17,20 @@ fun bar(vararg args: Any?) {
     foo(1, *args, 2, *args, 3)
 }
 
-@Test fun runTest() {
+fun box(): String {
     bar(null, true, "Hello")
+
+    assertEquals("""
+        1
+        null
+        true
+        Hello
+        2
+        null
+        true
+        Hello
+        3
+
+    """.trimIndent(), sb.toString())
+    return "OK"
 }