[strong] Introduce strong bit

test/mjsunit/strong/objects.js

Index: test/mjsunit/strong/objects.js
diff --git a/test/mjsunit/compiler/regress-416359.js b/test/mjsunit/strong/objects.js
similarity index 61%
copy from test/mjsunit/compiler/regress-416359.js
copy to test/mjsunit/strong/objects.js
index 18cdc5e72800ab16c49ea2f2091b88ba1c873248..4654606ab3a78d7b09708ec677de1a395df2d348 100644
--- a/test/mjsunit/compiler/regress-416359.js
+++ b/test/mjsunit/strong/objects.js
@@ -2,9 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-"use strict"
-function f() {
-  for (x in {a:0});
-}
+// Flags: --strong-mode --allow-natives-syntax
 
-assertThrows(f);
+'use strong';
+
+function f() {}
+assertTrue(%IsStrong(f));