Correctly handle Array unshift/splices that move elements past the max length of an Array

test/mjsunit/regress/regress-splice-large-index.js

 // Copyright 2013 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 20 matching lines @@
 assertEquals(0xffffffff, a.length);
 assertEquals(10, a[0xffffffff]);
 assertEquals(undefined, a[0xfffffffe]);
 
 a = [1,2,3];
 a[0xfffffffe] = 10;
 assertThrows("a.splice(1,1,7,7,7,7,7);", RangeError);
 assertEquals([1,7,7,7,7,7,3], a.slice(0, 7));
 assertEquals(0xffffffff, a.length);
 assertEquals(10, a[0xfffffffe + 5 - 1]);