[es6] Re-implement rest parameters via desugaring.

src/code-stubs.h

Index: src/code-stubs.h
diff --git a/src/code-stubs.h b/src/code-stubs.h
index f17fa07202d3e08f9aa1133c58732a21d3e527e4..bd7a3593338d0c3ffffcb829c5d760b937cf7444 100644
--- a/src/code-stubs.h
+++ b/src/code-stubs.h
@@ -110,8 +110,7 @@ namespace internal {
   V(StoreField)                             \
   V(StoreGlobal)                            \
   V(StoreTransition)                        \
-  V(StringLength)                           \
-  V(RestParamAccess)
+  V(StringLength)
 
 // List of code stubs only used on ARM 32 bits platforms.
 #if V8_TARGET_ARCH_ARM
@@ -1930,23 +1929,6 @@ class ArgumentsAccessStub: public PlatformCodeStub {
 };
 
 
-class RestParamAccessStub: public PlatformCodeStub {
- public:
-  explicit RestParamAccessStub(Isolate* isolate) : PlatformCodeStub(isolate) { }
-
-  CallInterfaceDescriptor GetCallInterfaceDescriptor() const override {
-    return ContextOnlyDescriptor(isolate());
-  }
-
- private:
-  void GenerateNew(MacroAssembler* masm);
-
-  void PrintName(std::ostream& os) const override;  // NOLINT
-
-  DEFINE_PLATFORM_CODE_STUB(RestParamAccess, PlatformCodeStub);
-};
-
-
 class RegExpExecStub: public PlatformCodeStub {
  public:
   explicit RegExpExecStub(Isolate* isolate) : PlatformCodeStub(isolate) { }