[es6] Handle conflicts for sloppy let

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.
 
-"use strict";
+// Flags: --no-legacy-const --harmony-sloppy
 
 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 19 matching lines @@
     return eval("(function(){ {" + s + "} return " + e + "})")();
   } catch (x) {
     return CheckException(x);
   }
 }
 
 function TestAll(expected,s,opt_e) {
   var e = "";
   var msg = s;
   if (opt_e) { e = opt_e; msg += opt_e; }
-  assertEquals(expected === 'LocalConflict' ? 'NoConflict' : expected,
-      TestGlobal(s,e), "global:'" + msg + "'");
+  // TODO(littledan): https://code.google.com/p/v8/issues/detail?id=4288
+  // It is also not clear whether these tests makes sense in sloppy mode.
+  // TODO(littledan): Add tests using Realm.eval to ensure that global eval
+  // works as expected.
+  // assertEquals(expected === 'LocalConflict' ? 'NoConflict' : expected,
+  //     TestGlobal(s,e), "global:'" + msg + "'");
   assertEquals(expected === 'LocalConflict' ? 'NoConflict' : expected,
       TestFunction(s,e), "function:'" + msg + "'");
   assertEquals(expected === 'LocalConflict' ? 'Conflict' : expected,
       TestBlock(s,e), "block:'" + msg + "'");
 }
 
 
 function TestConflict(s) {
   TestAll('Conflict', s);
-  TestAll('Conflict', 'eval("' + s + '");');
+  // TODO(littledan): https://code.google.com/p/v8/issues/detail?id=4288
+  // It is also not clear whether these tests makes sense in sloppy mode.
+  // TestAll('Conflict', 'eval("' + s + '");');
 }
 
 function TestNoConflict(s) {
   TestAll('NoConflict', s, "'NoConflict'");
-  TestAll('NoConflict', 'eval("' + s + '");', "'NoConflict'");
+  // TODO(littledan): https://code.google.com/p/v8/issues/detail?id=4288
+  // TestAll('NoConflict', 'eval("' + s + '");', "'NoConflict'");
 }
 
 function TestLocalConflict(s) {
   TestAll('LocalConflict', s, "'NoConflict'");
-  TestAll('NoConflict', 'eval("' + s + '");', "'NoConflict'");
+  // TODO(littledan): https://code.google.com/p/v8/issues/detail?id=4288
+  // It is also not clear whether these tests makes sense in sloppy mode.
+  // TestAll('NoConflict', 'eval("' + s + '");', "'NoConflict'");
 }
 
 var letbinds = [ "let x;",
                  "let x = 0;",
                  "let x = undefined;",
                  "let x = function() {};",
                  "let x, y;",
                  "let y, x;",
                  "const x = 0;",
                  "const x = undefined;",
@@ skipping 77 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 + '})();');