Prohibit let in lexical bindings

test/mjsunit/messages.js

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Flags: --stack-size=100 --harmony --harmony-reflect --harmony-regexps
-// Flags: --harmony-simd --strong-mode
+// Flags: --harmony-simd --strong-mode --harmony-sloppy --harmony-sloppy-let
 
 function test(f, expected, type) {
   try {
     f();
   } catch (e) {
     assertInstanceof(e, type);
     assertEquals(expected, e.message);
     return;
   }
   assertUnreachable("Exception expected");
@@ skipping 446 matching lines @@
   Number(1).toString(100);
 }, "toString() radix argument must be between 2 and 36", RangeError);
 
 
 // === URIError ===
 
 // kURIMalformed
 test(function() {
   decodeURI("%%");
 }, "URI malformed", URIError);
+
+// kLetInLexicalBinding

[adamk, 2015/10/05 18:29:26]

You don't need this anymore.

+test(function() {
+  eval('let let');
+}, "let is disallowed as a lexically bound name", SyntaxError);