JS backend: added jsCode test cases

js/js.translator/testData/jsCode/cases/switch.kt

@@ -0,0 +1,27 @@
+package foo
+
+fun testSwitch(number: Int): String = js("""
+    var result;
+
+    switch(number) {
+        case 1:
+            result = "one";
+            break;
+        case 2:
+            result = "two";
+            break;
+        default:
+            result = "don't know";
+            break;
+    }
+
+    return result;
+""")
+
+fun box(): String {
+    assertEquals("one", testSwitch(1))
+    assertEquals("two", testSwitch(2))
+    assertEquals("don't know", testSwitch(3))
+
+    return "OK"
+}