Introduce extended mode.

test/mjsunit/harmony/block-for.js

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
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 //       with the distribution.
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 //       from this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 // Flags: --harmony-scoping
 
+// TODO(ES6): properly activate extended mode
+"use strict";
+
 function props(x) {
   var array = [];
   for (let p in x) array.push(p);
   return array.sort();
 }
 
 assertEquals(0, props({}).length);
 assertEquals(1, props({x:1}).length);
 assertEquals(2, props({x:1, y:2}).length);
 
@@ skipping 43 matching lines @@
 for (let p in { get a() {}, b : 1}) { result += p; }
 assertEquals('ab', result);
 
 var result = '';
 for (let p in { get a() {}, set a(x) {}, b : 1}) { result += p; }
 assertEquals('ab', result);
 
 
 // Check that there is exactly one variable without initializer
 // in a for-in statement with let variables.
-assertThrows("function foo() { for (let in {}) { } }", SyntaxError);
-assertThrows("function foo() { for (let x = 3 in {}) { } }", SyntaxError);
-assertThrows("function foo() { for (let x, y in {}) { } }", SyntaxError);
-assertThrows("function foo() { for (let x = 3, y in {}) { } }", SyntaxError);
-assertThrows("function foo() { for (let x, y = 4 in {}) { } }", SyntaxError);
-assertThrows("function foo() { for (let x = 3, y = 4 in {}) { } }", SyntaxError);
+// TODO(ES6): properly activate extended mode
+assertThrows("function foo() { 'use strict'; for (let in {}) { } }", SyntaxError);
+assertThrows("function foo() { 'use strict'; for (let x = 3 in {}) { } }", SyntaxError);
+assertThrows("function foo() { 'use strict'; for (let x, y in {}) { } }", SyntaxError);
+assertThrows("function foo() { 'use strict'; for (let x = 3, y in {}) { } }", SyntaxError);
+assertThrows("function foo() { 'use strict'; for (let x, y = 4 in {}) { } }", SyntaxError);
+assertThrows("function foo() { 'use strict'; for (let x = 3, y = 4 in {}) { } }", SyntaxError);
 
 
 // In a normal for statement the iteration variable is not
 // freshly allocated for each iteration.
 function closures1() {
   let a = [];
   for (let i = 0; i < 5; ++i) {
     a.push(function () { return i; });
   }
   for (let j = 0; j < 5; ++j) {
@@ skipping 24 matching lines @@
   for (let p in x) {
     a.push(function () { return p; });
   }
   let k = 0;
   for (let q in x) {
     assertEquals(q, a[k]());
     ++k;
   }
 }
 closures3({a : [0], b : 1, c : {v : 1}, get d() {}, set e(x) {}});