[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 a1e015812549de6234352a85b10e6e133a144691..f3106e6f41f8235e21a31a22393e8efbf1084863 100644
--- a/src/code-stubs.h
+++ b/src/code-stubs.h
@@ -109,8 +109,7 @@ 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
@@ -1929,23 +1928,6 @@ 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) { }