Support rest parameters in arrow functions

src/parser.h

Index: src/parser.h
diff --git a/src/parser.h b/src/parser.h
index d092403e7af1fb01e3298d6b53bcaa1c9b4090d9..c950fb48e5d2f338fd06b592f881b733ecaf5631 100644
--- a/src/parser.h
+++ b/src/parser.h
@@ -757,13 +757,9 @@ class ParserTraits {
   V8_INLINE void DeclareFormalParameter(Scope* scope, const AstRawString* name,
                                         ExpressionClassifier* classifier,
                                         bool is_rest);
-  void DeclareArrowFunctionParameters(Scope* scope, Expression* expr,
-                                      const Scanner::Location& params_loc,
-                                      Scanner::Location* duplicate_loc,
-                                      bool* ok);
   void ParseArrowFunctionFormalParameters(Scope* scope, Expression* params,
                                           const Scanner::Location& params_loc,
-                                          bool* is_rest,
+                                          bool has_rest,
                                           Scanner::Location* duplicate_loc,
                                           bool* ok);