Implement handling of arrow functions in the parser

src/parser.h

Index: src/parser.h
diff --git a/src/parser.h b/src/parser.h
index f49626766eb1dab32ea2bddb5d99289aa91ecd10..d924cdf57db60ad6f0e02b8fe1b3340daa67493a 100644
--- a/src/parser.h
+++ b/src/parser.h
@@ -587,7 +587,8 @@ class ParserTraits {
       Handle<String> name,
       Scanner::Location function_name_location,
       bool name_is_strict_reserved,
-      bool is_generator,
+      FunctionParsingMode parsing_mode,
+      Expression* params_ast,
       int function_token_position,
       FunctionLiteral::FunctionType type,
       bool* ok);
@@ -732,11 +733,15 @@ class Parser : public ParserBase<ParserTraits> {
                                   Expression* subject,
                                   Statement* body);
 
+  Vector<VariableProxy*> ParameterListFromExpression(Expression* expression,
+                                                     bool* ok);
+
   FunctionLiteral* ParseFunctionLiteral(
       Handle<String> name,
       Scanner::Location function_name_location,
       bool name_is_strict_reserved,
-      bool is_generator,
+      FunctionParsingMode parsing_mode,
+      Expression* params_ast,
       int function_token_position,
       FunctionLiteral::FunctionType type,
       bool* ok);