Adding checks for the cases when array grows too big.

test/mjsunit/array-unshift.js

 // Copyright 2010 the V8 project authors. All rights reserved.
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 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
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@@ skipping 96 matching lines @@
   assertEquals(array[3], Array.prototype[3]);
   assertFalse(array.hasOwnProperty(3));
 
   assertEquals(array[7], Array.prototype[7]);
   assertFalse(array.hasOwnProperty(7));
 
   assertTrue(delete Array.prototype[3]);
   assertTrue(delete Array.prototype[5]);
   assertTrue(delete Array.prototype[7]);
 })();
+
+// Check the behaviour when approaching maximal values for length.
+(function() {
+  for (var i = 0; i < 7; i++) {
+    try {
+      new Array((1 << 32) - 3).unshift(1, 2, 3, 4, 5);
+      throw 'Should have thrown RangeError';
+    } catch (e) {
+      assertTrue(e instanceof RangeError);
+    }
+
+    // Check smi boundary
+    var bigNum = (1 << 30) - 3;
+    assertEquals(bigNum + 7, new Array(bigNum).unshift(1, 2, 3, 4, 5, 6, 7));
+  }
+})();