JS: move more test to box tests

js/js.translator/testData/box/reified/isClass.kt

@@ -0,0 +1,25 @@
+package foo
+
+// CHECK_NOT_CALLED: isInstance
+
+interface A
+interface B
+
+open class C : A, B
+
+class D : C()
+
+fun box(): String {
+    assertEquals(false, isInstance<A>(0))
+    assertEquals(false, isInstance<A>(""))
+    assertEquals(true, isInstance<A>(C()))
+    assertEquals(true, isInstance<A>(D()))
+    assertEquals(true, isInstance<D>(D()))
+    assertEquals(true, isInstance<C>(D()))
+
+    assertEquals(true, isInstance<D?>(D()), "isInstance<D?>(D())")
+    assertEquals(true, isInstance<D?>(null), "isInstance<D?>(null)")
+    assertEquals(false, isInstance<D?>(C()), "isInstance<D?>(C())")
+
+    return "OK"
+}