Use SetOwnElement when creating splice records in array length setter

test/mjsunit/es7/regress/regress-443982.js

Index: test/mjsunit/es7/regress/regress-443982.js
diff --git a/test/mjsunit/es7/regress/regress-443982.js b/test/mjsunit/es7/regress/regress-443982.js
new file mode 100644
index 0000000000000000000000000000000000000000..5a2e9cd6db7c2ab897db296b94e6eb1c14fe7fb8
--- /dev/null
+++ b/test/mjsunit/es7/regress/regress-443982.js
@@ -0,0 +1,22 @@
+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+var records;
+function observer(r) {
+  records = r;
+}
+
+Object.defineProperty(Array.prototype, '0', {
+  get: function() { return 0; },
+  set: function() { throw "boom!"; }
+});
+arr = [1, 2];
+Array.observe(arr, observer);
+arr.length = 0;
+assertEquals(0, arr.length);
+
+Object.deliverChangeRecords(observer);
+assertEquals(1, records.length);
+assertEquals('splice', records[0].type);
+assertArrayEquals([1, 2], records[0].removed);