[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/kt16412.kt

@@ -0,0 +1,23 @@
+// DONT_TARGET_EXACT_BACKEND: JS JS_IR JS_IR_ES6 WASM NATIVE
+// MODULE: lib
+// FILE: MFunction.java
+
+public interface MFunction<T, R> {
+    R invoke(T t);
+}
+
+// MODULE: main(lib)
+// FILE: 1.kt
+
+
+object Foo {
+    class Requester(val dealToBeOffered: String)
+}
+
+class Bar {
+    val foo = MFunction(Foo::Requester)
+}
+
+fun box(): String {
+    return Bar().foo("OK").dealToBeOffered
+}