[strong] Deprecate for-in

test/mjsunit/strong/for-in.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: --strong-mode
+
+(function NoForInStatement() {
+  assertThrows("'use strong'; for (x in []);", SyntaxError);
+  assertThrows("'use strong'; for (let x in []);", SyntaxError);
+  assertThrows("'use strong'; for (const x in []);", SyntaxError);
+  assertThrows("'use strong'; for (var x in []);", SyntaxError);
+  assertThrows("'use strong'; for (var x = 0 in []);", SyntaxError);

[marja, 2015/02/19 12:34:22]

Can we has tests that for of still works?

(In general, how are we going to test that the stuff we want to keep working
stays working? Should we have a list of tests which should also work w/ strong
mode and then run them w/ strong mode, so that we don't need to duplicate them?)

[rossberg, 2015/02/19 13:23:05]

Done. Also removed the nonsensical var tests, since that's illegal anyway.
Good question. Most existing tests will probably not work, for 'var' alone.
Maybe it's good enough to have a number of dedicated strong mode test programs.
If something really gets ruled out accidentally then I suppose we gonna find out
relatively quickly...

+})();