[es6] parse arrow ConciseBody with accept_IN flag

src/ast.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_AST_H_
 #define V8_AST_H_
 
 #include "src/assembler.h"
 #include "src/ast-value-factory.h"
 #include "src/bailout-reason.h"
@@ skipping 2529 matching lines @@
   }
   const FeedbackVectorSpec* feedback_vector_spec() const {
     return ast_properties_.get_spec();
   }
   bool dont_optimize() { return dont_optimize_reason_ != kNoReason; }
   BailoutReason dont_optimize_reason() { return dont_optimize_reason_; }
   void set_dont_optimize_reason(BailoutReason reason) {
     dont_optimize_reason_ = reason;
   }
 
+  bool accept_IN() const { return AcceptInHintBit::decode(bitfield_); }
+  void set_accept_IN(bool value) {
+    bitfield_ = AcceptInHintBit::update(bitfield_, value);
+  }
+
  protected:
   FunctionLiteral(Zone* zone, const AstRawString* name,
                   AstValueFactory* ast_value_factory, Scope* scope,
                   ZoneList<Statement*>* body, int materialized_literal_count,
                   int expected_property_count, int parameter_count,
                   FunctionType function_type,
                   ParameterFlag has_duplicate_parameters,
                   IsFunctionFlag is_function,
                   EagerCompileHint eager_compile_hint, FunctionKind kind,
                   int position)
@@ skipping 37 matching lines @@
   unsigned bitfield_;
   class IsExpression : public BitField<bool, 0, 1> {};
   class IsAnonymous : public BitField<bool, 1, 1> {};
   class Pretenure : public BitField<bool, 2, 1> {};
   class HasDuplicateParameters : public BitField<ParameterFlag, 3, 1> {};
   class IsFunction : public BitField<IsFunctionFlag, 4, 1> {};
   class EagerCompileHintBit : public BitField<EagerCompileHint, 5, 1> {};
   class FunctionKindBits : public BitField<FunctionKind, 6, 8> {};
   class ShouldBeUsedOnceHintBit : public BitField<ShouldBeUsedOnceHint, 15, 1> {
   };
+  // Used for lazily compiled arrow functions
+  class AcceptInHintBit : public BitField<bool, 16, 1> {};
 };
 
 
 class ClassLiteral final : public Expression {
  public:
   typedef ObjectLiteralProperty Property;
 
   DECLARE_NODE_TYPE(ClassLiteral)
 
   Handle<String> name() const { return raw_name_->string(); }
@@ skipping 998 matching lines @@
   // the parser-level zone.
   Zone* parser_zone_;
   AstValueFactory* ast_value_factory_;
 };
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_AST_H_