[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/varargs/varargsOverride.kt

@@ -0,0 +1,21 @@
+// DONT_TARGET_EXACT_BACKEND: JS JS_IR JS_IR_ES6 WASM NATIVE
+// MODULE: lib
+// FILE: A.java
+
+public abstract class A<T> {
+    protected abstract String doIt(T... args);
+
+    public String test(T... args) {
+        return doIt(args);
+    }
+}
+
+// MODULE: main(lib)
+// FILE: 1.kt
+
+val a: A<Void> =
+    object : A<Void>() {
+        override fun doIt(vararg parameters: Void): String = "OK"
+    }
+
+fun box(): String = a.test()

compiler/testData/codegen/box/varargs/varargsOverride2.kt

@@ -0,0 +1,24 @@
+// DONT_TARGET_EXACT_BACKEND: JS JS_IR JS_IR_ES6 WASM NATIVE
+// MODULE: lib
+// FILE: A.java
+
+public abstract class A<T> {
+    protected abstract String doIt(T... args);
+
+    public <S extends T> String test(S... args) {
+        return doIt(args);
+    }
+}
+
+// MODULE: main(lib)
+// FILE: 1.kt
+
+open class Super
+class Sub: Super()
+
+val a: A<Super> =
+    object : A<Super>() {
+        override fun doIt(vararg parameters: Super): String = "OK"
+    }
+
+fun box(): String = a.test<Sub>()

compiler/testData/codegen/box/varargs/varargsOverride3.kt

@@ -0,0 +1,41 @@
+// IGNORE_BACKEND_FIR: JVM_IR
+// DONT_TARGET_EXACT_BACKEND: JS JS_IR JS_IR_ES6 WASM NATIVE
+// MODULE: lib
+// FILE: A.java
+
+public abstract class A<T> {
+    protected abstract String doIt(T... args);
+
+    class B<S extends T, U extends S> {
+        public String test(T... args) {
+            return doIt(args);
+        }
+
+        public String test2(S... args) {
+            return doIt(args);
+        }
+
+        public String test3(U... args) {
+            return doIt(args);
+        }
+    }
+}
+
+// MODULE: main(lib)
+// FILE: 1.kt
+
+open class Super
+open class Sub: Super()
+class Sub2: Sub()
+
+val a: A<Super> =
+    object : A<Super>() {
+        override fun doIt(vararg parameters: Super): String = "OK"
+    }
+
+fun box(): String {
+    val b = a.B<Sub, Sub2>()
+    if (b.test() != "OK") return "FAIL1"
+    if (b.test2() != "OK") return "FAIL2"
+    return b.test3()
+}