[JS IR BE] Fix and refactor interop tests

js/js.translator/testData/box/native/eval.kt

@@ -1,6 +1,4 @@
-// IGNORE_BACKEND: JS_IR
 // SKIP_MINIFICATION
-package foo
 
 val top = "TOP LEVEL"
 
@@ -11,7 +9,7 @@ fun box(): String {
 
     assertEquals(5, eval("3 + 2"))
 
-    val PACKAGE = "JS_TESTS.foo"
+    val PACKAGE = "JS_TESTS"
     assertEquals(top, eval("$PACKAGE.top"))
 
     return "OK"