Drop previously deprecated API

- common and JS org.junit.Test from kotlin.test
- kotlin.Synchronized/Volatile from K/JS
- JS 'native' annotation

libraries/kotlin.test/js/src/main/kotlin/org/junit/junitTest.kt

@@ -1,13 +0,0 @@
-/*
- * Copyright 2010-2018 JetBrains s.r.o. and Kotlin Programming Language contributors.
- * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
- */
-
-package org.junit
-
-@Deprecated(
-    "Use 'Test' from kotlin.test package",
-    replaceWith = ReplaceWith("kotlin.test.Test", "kotlin.test.Test"),
-    level = DeprecationLevel.ERROR
-)
-actual typealias Test = kotlin.test.Test