Fix await/async/yield keyword recognition

runtime/vm/parser.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_PARSER_H_
 #define VM_PARSER_H_
 
 #include "include/dart_api.h"
 
 #include "platform/assert.h"
@@ skipping 303 matching lines @@
     tokens_iterator_.Advance();
     CompilerStats::num_tokens_consumed++;
   }
   void ConsumeRightAngleBracket();
   void CheckToken(Token::Kind token_expected, const char* msg = NULL);
   void ExpectToken(Token::Kind token_expected);
   void ExpectSemicolon();
   void UnexpectedToken();
   String* ExpectUserDefinedTypeIdentifier(const char* msg);
   String* ExpectIdentifier(const char* msg);
-  bool IsLiteral(const char* literal);
   bool IsAwaitKeyword();
   bool IsYieldKeyword();
 
   void SkipIf(Token::Kind);
   void SkipBlock();
   intptr_t SkipMetadata();
   void SkipToMatchingParenthesis();
   void SkipTypeArguments();
   void SkipType(bool allow_void);
   void SkipInitializers();
@@ skipping 309 matching lines @@
                                     bool is_const,
                                     SequenceNode** await_preamble);
   AstNode* ParseVariableDeclarationList();
   AstNode* ParseFunctionStatement(bool is_literal);
   AstNode* ParseYieldStatement();
   AstNode* ParseStatement();
   SequenceNode* ParseNestedStatement(bool parsing_loop_body,
                                      SourceLabel* label);
   void ParseStatementSequence();
   bool IsIdentifier();
+  bool IsSymbol(const String& symbol);
   bool IsSimpleLiteral(const AbstractType& type, Instance* value);
   bool IsFunctionTypeAliasName();
   bool IsMixinAppAlias();
   bool TryParseQualIdent();
   bool TryParseTypeParameters();
   bool TryParseOptionalType();
   bool TryParseReturnType();
   bool IsVariableDeclaration();
   bool IsFunctionDeclaration();
   bool IsFunctionLiteral();
@@ skipping 194 matching lines @@
 
   // Indentation of parser trace.
   intptr_t trace_indent_;
 
   DISALLOW_COPY_AND_ASSIGN(Parser);
 };
 
 }  // namespace dart
 
 #endif  // VM_PARSER_H_