JS: move expressions test to box tests

js/js.translator/testData/box/expression/misc/kt9443.kt

@@ -0,0 +1,20 @@
+package foo
+
+abstract class BaseClass {
+    protected open val menuId: Int = 0
+
+    public fun run(): Pair<String, Boolean> =
+            "$menuId" to (menuId == 0)
+}
+
+class ImplClass: BaseClass() {
+    override val menuId: Int = 3
+}
+
+public fun box(): String {
+    val result = ImplClass().run()
+
+    if (result != ("3" to false)) return "Fail: $result"
+
+    return "OK"
+}