fix implicit_scope_test and builtin_identifier_test

lib/src/codegen/js_names.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library dev_compiler.src.codegen.js_names;
 
 import 'dart:collection';
 import 'package:dev_compiler/src/js/js_ast.dart';
 
 /// Unique instance for temporary variables. Will be renamed consistently
@@ skipping 210 matching lines @@
 bool needsRename(Identifier node) =>
     node is TemporaryId || node.allowRename && invalidVariableName(node.name);
 
 Object /*String|TemporaryId*/ identifierKey(Identifier node) =>
     node is TemporaryId ? node : node.name;
 
 /// Returns true for invalid JS variable names, such as keywords.
 /// Also handles invalid variable names in strict mode, like "arguments".
 bool invalidVariableName(String keyword, {bool strictMode: true}) {
   switch (keyword) {
+    // http://www.ecma-international.org/ecma-262/6.0/#sec-future-reserved-words
+    case "await":
+
     case "break":
     case "case":
     case "catch":
     case "class":
     case "const":
     case "continue":
     case "debugger":
     case "default":
     case "delete":
     case "do":
     case "else":
+    case "enum":
     case "export":
     case "extends":
     case "finally":
     case "for":
     case "function":
     case "if":
     case "import":
     case "in":
     case "instanceof":
-    case "interface":
     case "let":
     case "new":
     case "return":
-    case "static":
     case "super":
     case "switch":
     case "this":
     case "throw":
     case "try":
     case "typeof":
     case "var":
     case "void":
     case "while":
     case "with":
-    case "yield":
       return true;
     case "arguments":
     case "eval":
+    // http://www.ecma-international.org/ecma-262/6.0/#sec-future-reserved-words
+    // http://www.ecma-international.org/ecma-262/6.0/#sec-identifiers-static-semantics-early-errors
+    case "implements":
+    case "interface":
+    case "let":
+    case "package":
+    case "private":
+    case "protected":
+    case "public":
+    case "static":
+    case "yield":
       return strictMode;
   }
   return false;
 }
 
 /// Returns true for invalid static field names in strict mode.
 /// In particular, "caller" "callee" and "arguments" cannot be used.
 bool invalidStaticFieldName(String name) {
   switch (name) {
     case "arguments":
     case "caller":
     case "callee":
       return true;
   }
   return false;
 }