[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/delegation/delegationAndInheritanceFromJava.kt

@@ -0,0 +1,21 @@
+// DONT_TARGET_EXACT_BACKEND: JS JS_IR JS_IR_ES6 WASM NATIVE
+// MODULE: lib
+// FILE: Foo.java
+
+import java.util.Set;
+
+public class Foo {
+    public interface A extends Set<String> {}
+
+    public interface B extends Set<String> {}
+}
+
+// MODULE: main(lib)
+// FILE: 1.kt
+
+import Foo.*
+import java.util.HashSet
+
+class Impl(b: B): A, B by b
+
+fun box() = "OK"