Move delete-last-fast-property code from CSA to C++

test/mjsunit/regress/regress-crbug-714981.js

+// Copyright 2017 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.
+
+function addProperties(o)
+{
+    o.p1 = 1;
+    o.p2 = 2;
+    o.p3 = 3;
+    o.p4 = 4;
+    o.p5 = 5;
+    o.p6 = 6;
+    o.p7 = 7;
+    o.p8 = 8;
+}
+function removeProperties(o)
+{
+    delete o.p8;
+    delete o.p7;
+    delete o.p6;
+    delete o.p5;
+}
+function makeO()
+{
+    var o = { };
+    addProperties(o);
+    removeProperties(o);
+    addProperties(o);
+}
+for (var i = 0; i < 3; ++i) {
+    o = makeO();
+}