JS: move expressions test to box tests

js/js.translator/testData/box/dynamic/incrementAndDecrement.kt

@@ -0,0 +1,28 @@
+package foo
+
+fun box(): String {
+    var a: dynamic = 12
+    var b: dynamic = 33.4
+    var c: dynamic = "text"
+    val d: dynamic = true
+
+    assertEquals(11, --a)
+    assertEquals(11, a)
+    assertEquals(11, a--)
+    assertEquals(10, a)
+    assertEquals(10, a++)
+    assertEquals(11, a)
+    assertEquals(12, ++a)
+    assertEquals(12, a)
+
+    assertEquals(32.4, --b)
+    assertEquals(32.4, b)
+    assertEquals(32.4, b--)
+    assertEquals(31.4, b)
+    assertEquals(31.4, b++)
+    assertEquals(32.4, b)
+    assertEquals(33.4, ++b)
+    assertEquals(33.4, b)
+
+    return "OK"
+}