Remove hand-written assembly ArrayPush stubs

test/mjsunit/array-push6.js

+// 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.
+
+// Flags: --allow-natives-syntax
+
+function push_wrapper(array, value) {
+  array.push(value);
+}
+
+// Test that optimization of Array.push() for non-Arrays works correctly.
+var object = { x : 8, length: 3 };
+object[18] = 5;
+object.__proto__ = Array.prototype;
+push_wrapper(object, 1);
+push_wrapper(object, 1);
+assertEquals(5, object.length);
+%OptimizeFunctionOnNextCall(push_wrapper);
+push_wrapper(object, 1);
+push_wrapper(object, 1);
+assertEquals(8, object.x);
+assertEquals(7, object.length);