JS: move more test to box tests

js/js.translator/testData/box/trait/funDelegation.kt

@@ -0,0 +1,22 @@
+package foo
+
+open class Base() {
+    fun n(n: Int): Int = n + 1
+}
+
+interface Abstract {
+}
+
+class Derived1() : Base(), Abstract {
+}
+class Derived2() : Abstract, Base() {
+}
+
+fun test(s: Base): Boolean = s.n(238) == 239
+
+fun box(): String {
+    if (!test(Base())) return "Fail #1"
+    if (!test(Derived1())) return "Fail #2"
+    if (!test(Derived2())) return "Fail #3"
+    return "OK"
+}