Split off a separate --harmony_sloppy_let flag

test/mjsunit/harmony/block-conflicts-sloppy.js

 // Copyright 2011 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.
 
 // Test for conflicting variable bindings.
 
-// Flags: --no-legacy-const --harmony-sloppy
+// Flags: --no-legacy-const --harmony-sloppy --harmony-sloppy-let
 
 function CheckException(e) {
   var string = e.toString();
   assertTrue(string.indexOf("has already been declared") >= 0 ||
              string.indexOf("redeclaration") >= 0);
   return 'Conflict';
 }
 
 
 function TestGlobal(s,e) {
@@ skipping 147 matching lines @@
 // Test conflicting parameter/var bindings.
 for (var v = 0; v < varbinds.length; ++v) {
   TestNoConflict('(function (x) {' + varbinds[v] + '})();');
 }
 
 // Test conflicting catch/function bindings.
 TestNoConflict('try {} catch(x) {' + funbind + '}');
 
 // Test conflicting parameter/function bindings.
 TestNoConflict('(function (x) {' + funbind + '})();');