[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/callableReference/staticMethod.kt

@@ -0,0 +1,18 @@
+// DONT_TARGET_EXACT_BACKEND: JS JS_IR JS_IR_ES6 WASM NATIVE
+// MODULE: lib
+// FILE: A.java
+
+class A {
+    public static void main(String[] args) {
+        args[0] = "OK";
+    }
+}
+
+// MODULE: main(lib)
+// FILE: 1.kt
+
+fun box(): String {
+    val args = arrayOf("Fail")
+    (A::main)(args)
+    return args[0]
+}