[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 5e2c4e76b408afea089282f4cd13020d8dd8bb01..36c74af6c49ad32a4d1c6e45e61f4e388b4450bb 100644
--- a/src/code-stubs.cc
+++ b/src/code-stubs.cc
@@ -862,11 +862,6 @@ void ArgumentsAccessStub::Generate(MacroAssembler* masm) {
 }
 
 
-void RestParamAccessStub::Generate(MacroAssembler* masm) {
-  GenerateNew(masm);
-}
-
-
 void ArgumentsAccessStub::PrintName(std::ostream& os) const {  // NOLINT
   os << "ArgumentsAccessStub_";
   switch (type()) {
@@ -887,11 +882,6 @@ 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();
 }