Fix Array.prototype.concat when exceeding array size limit.

src/array.js

 // Copyright 2012 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
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 465 matching lines @@
   }
 
   var array = ToObject(this);
   var arg_count = %_ArgumentsLength();
   var arrays = new InternalArray(1 + arg_count);
   arrays[0] = array;
   for (var i = 0; i < arg_count; i++) {
     arrays[i + 1] = %_Arguments(i);
   }
 
-  return %ArrayConcat(arrays);
+  var result = %ArrayConcat(arrays);
+  if (!%_IsSmi(result)) return result;
+
+  // The result is a smi as signal that %ArrayConcat failed because the result
+  // exceeds the array size limit. Overflowing elements turn into properties.
+  var offset = 0;
+  var result = [];
+  for (var i = 0; i < arrays.length; i++) {
+    var array = arrays[i];
+    var keys = GetSortedArrayKeys(array, %GetArrayKeys(array, array.length));
+    for (var j = 0; j < keys.length; j++) {
+      var key = keys[j];
+      result[key + offset] = array[key];
+    }
+    offset += array.length;
+  }
+  return result;
 }
 
 
 // For implementing reverse() on large, sparse arrays.
 function SparseReverse(array, len) {
   var keys = GetSortedArrayKeys(array, %GetArrayKeys(array, len));
   var high_counter = keys.length - 1;
   var low_counter = 0;
   while (low_counter <= high_counter) {
     var i = keys[low_counter];
@@ skipping 1065 matching lines @@
   ));
 
   SetUpLockedPrototype(InternalPackedArray, $Array(), $Array(
     "join", getFunction("join", ArrayJoin),
     "pop", getFunction("pop", ArrayPop),
     "push", getFunction("push", ArrayPush)
   ));
 }
 
 SetUpArray();