[es6] re-implement rest parameters via desugaring

src/code-stubs.cc

Index: src/code-stubs.cc
diff --git a/src/code-stubs.cc b/src/code-stubs.cc
index 3b41f9e60934eef6adef9df64667bcc41ea9c939..624791f967063975c565378c6772c579468694ca 100644
--- a/src/code-stubs.cc
+++ b/src/code-stubs.cc
@@ -869,11 +869,6 @@ void ArgumentsAccessStub::Generate(MacroAssembler* masm) {
 }
 
 
-void RestParamAccessStub::Generate(MacroAssembler* masm) {
-  GenerateNew(masm);
-}
-
-
 void ArgumentsAccessStub::PrintName(std::ostream& os) const {  // NOLINT
   os << "ArgumentsAccessStub_";
   switch (type()) {
@@ -894,11 +889,6 @@ void ArgumentsAccessStub::PrintName(std::ostream& os) const {  // NOLINT
 }
 
 
-void RestParamAccessStub::PrintName(std::ostream& os) const {  // NOLINT
-  os << "RestParamAccessStub_";
-}
-
-
 void CallFunctionStub::PrintName(std::ostream& os) const {  // NOLINT
   os << "CallFunctionStub_Args" << argc();
 }