Implement handling of arrow functions in the parser

src/ast.h

Index: src/ast.h
diff --git a/src/ast.h b/src/ast.h
index 0115d988272c44e64f326d6f7377619824f2ea41..73d861c07f1e1067a0b48b1b00b09cc39d869944 100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -2287,9 +2287,10 @@ class FunctionLiteral V8_FINAL : public Expression {
     kNotParenthesized
   };
 
-  enum IsGeneratorFlag {
-    kIsGenerator,
-    kNotGenerator
+  enum KindFlag {
+    kNormalFunction,
+    kArrowFunction,
+    kGeneratorFunction
   };
 
   DECLARE_NODE_TYPE(FunctionLiteral)
@@ -2350,9 +2351,8 @@ class FunctionLiteral V8_FINAL : public Expression {
     bitfield_ = IsParenthesized::update(bitfield_, kIsParenthesized);
   }
 
-  bool is_generator() {
-    return IsGenerator::decode(bitfield_) == kIsGenerator;
-  }
+  bool is_generator() { return IsGenerator::decode(bitfield_); }
+  bool is_arrow() { return IsArrow::decode(bitfield_); }
 
   int ast_node_count() { return ast_properties_.node_count(); }
   AstProperties::Flags* flags() { return ast_properties_.flags(); }
@@ -2381,7 +2381,7 @@ class FunctionLiteral V8_FINAL : public Expression {
                   ParameterFlag has_duplicate_parameters,
                   IsFunctionFlag is_function,
                   IsParenthesizedFlag is_parenthesized,
-                  IsGeneratorFlag is_generator,
+                  KindFlag kind,
                   int position)
       : Expression(zone, position),
         name_(name),
@@ -2401,7 +2401,8 @@ class FunctionLiteral V8_FINAL : public Expression {
         HasDuplicateParameters::encode(has_duplicate_parameters) |
         IsFunction::encode(is_function) |
         IsParenthesized::encode(is_parenthesized) |
-        IsGenerator::encode(is_generator);
+        IsGenerator::encode(kind == kGeneratorFunction) |
+        IsArrow::encode(kind == kArrowFunction);
   }
 
  private:
@@ -2426,7 +2427,8 @@ class FunctionLiteral V8_FINAL : public Expression {
   class HasDuplicateParameters: public BitField<ParameterFlag, 3, 1> {};
   class IsFunction: public BitField<IsFunctionFlag, 4, 1> {};
   class IsParenthesized: public BitField<IsParenthesizedFlag, 5, 1> {};
-  class IsGenerator: public BitField<IsGeneratorFlag, 6, 1> {};
+  class IsGenerator: public BitField<bool, 6, 1> {};
+  class IsArrow: public BitField<bool, 7, 1> {};
 };
 
 
@@ -3303,13 +3305,13 @@ class AstNodeFactory V8_FINAL BASE_EMBEDDED {
       FunctionLiteral::FunctionType function_type,
       FunctionLiteral::IsFunctionFlag is_function,
       FunctionLiteral::IsParenthesizedFlag is_parenthesized,
-      FunctionLiteral::IsGeneratorFlag is_generator,
+      FunctionLiteral::KindFlag kind,
       int position) {
     FunctionLiteral* lit = new(zone_) FunctionLiteral(
         zone_, name, scope, body,
         materialized_literal_count, expected_property_count, handler_count,
         parameter_count, function_type, has_duplicate_parameters, is_function,
-        is_parenthesized, is_generator, position);
+        is_parenthesized, kind, position);
     // Top-level literal doesn't count for the AST's properties.
     if (is_function == FunctionLiteral::kIsFunction) {
       visitor_.VisitFunctionLiteral(lit);