Try to switch Array builtins into strict mode.

test/mjsunit/object-freeze.js

 // Copyright 2010 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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@@ skipping 304 matching lines @@
 assertTrue(%HasFastProperties(obj));
 assertTrue(Object.isFrozen(obj));
 
 // Test array built-in functions with freeze.
 obj = [1,2,3];
 Object.freeze(obj);
 // if frozen implies sealed, then the tests in object-seal.js are mostly
 // sufficient.
 assertTrue(Object.isSealed(obj));
 
-assertDoesNotThrow(function() { obj.push(); });
-assertDoesNotThrow(function() { obj.unshift(); });
-assertDoesNotThrow(function() { obj.splice(0,0); });
+// Verify that the length can't be written by builtins.
+assertThrows(function() { obj.push(); }, TypeError);
+assertThrows(function() { obj.unshift(); }, TypeError);
+assertThrows(function() { obj.splice(0,0); }, TypeError);
 assertTrue(Object.isFrozen(obj));
 
 // Verify that an item can't be changed with splice.
 assertThrows(function() { obj.splice(0,1,1); }, TypeError);
+assertTrue(Object.isFrozen(obj));
 
 // Verify that unshift() with no arguments will fail if it reifies from
 // the prototype into the object.
 obj = [1,,3];
 obj.__proto__[1] = 1;
 assertEquals(1, obj[1]);
 Object.freeze(obj);
 assertThrows(function() { obj.unshift(); }, TypeError);