[es7] Implement async functions parsing

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 2628 matching lines @@
   int parameter_count_;
   int function_token_position_;
 
   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> {
+  class FunctionKindBits : public BitField<FunctionKind, 6, 9> {};
+  class ShouldBeUsedOnceHintBit : public BitField<ShouldBeUsedOnceHint, 16, 1> {
   };
 };
 
 
 class ClassLiteral final : public Expression {
  public:
   typedef ObjectLiteralProperty Property;
 
   DECLARE_NODE_TYPE(ClassLiteral)
 
@@ skipping 1006 matching lines @@
   // the parser-level zone.
   Zone* parser_zone_;
   AstValueFactory* ast_value_factory_;
 };
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_AST_H_