Revert of [es6] implement default parameters via desugaring

test/mjsunit/harmony/default-parameters-lazy.js

-// Copyright 2015 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: --harmony-default-parameters --min-preparse-length=0
-
-var i = 0;
-function f(handler = function(b) { return b + "#" + (++i); }, b = "red") {
-  return handler(b);
-}
-
-assertEquals([
-  "blue#1",
-  "red#2",
-  "red",
-  "yellow#3"
-], [
-  f(undefined, "blue"),
-  f(),
-  f(function(b) { return b; }),
-  f(undefined, "yellow")
-]);