[Test] Properly merge box against java testdata into codegen/box

Previous commit about it was 3199ce03 and it was completely wrong

compiler/testData/codegen/box/enum/simpleJavaInnerEnum.kt

@@ -0,0 +1,21 @@
+// DONT_TARGET_EXACT_BACKEND: JS JS_IR JS_IR_ES6 WASM NATIVE
+// MODULE: lib
+// FILE: test/Foo.java
+
+package test;
+
+public class Foo {
+    public enum MyEnum {
+        A;
+    }
+}
+
+// MODULE: main(lib)
+// FILE: 1.kt
+
+import test.*
+import test.Foo.MyEnum.A
+
+fun box() =
+    if (Foo.MyEnum.A.toString() == "A" && A.toString() == "A") "OK"
+    else "fail"