[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/staticMethod.kt

@@ -0,0 +1,18 @@
+// DONT_TARGET_EXACT_BACKEND: JS JS_IR JS_IR_ES6 WASM NATIVE
+// MODULE: lib
+// FILE: test/En.java
+
+package test;
+
+public enum En {
+    ENTRY;
+    
+    public static String foo() {
+        return "OK";
+    }
+}
+
+// MODULE: main(lib)
+// FILE: 1.kt
+
+fun box() = test.En.foo()