Enable await in while and do-while.

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 610 matching lines @@
   bool IsForInStatement();
   bool IsTopLevelAccessor();
 
   AstNode* ParseBinaryExpr(int min_preced);
   LiteralNode* ParseConstExpr();
   static const bool kRequireConst = true;
   static const bool kAllowConst = false;
   static const bool kConsumeCascades = true;
   static const bool kNoCascades = false;
   AstNode* ParseAwaitableExpr(bool require_compiletime_const,
-                              bool consume_cascades);
+                              bool consume_cascades,
+                              SequenceNode** await_preamble);
   AstNode* ParseExpr(bool require_compiletime_const, bool consume_cascades);
   AstNode* ParseExprList();
   AstNode* ParseConditionalExpr();
   AstNode* ParseUnaryExpr();
   AstNode* ParsePostfixExpr();
   AstNode* ParseSelectors(AstNode* primary, bool is_cascade);
   AstNode* ParseCascades(AstNode* expr);
   AstNode* ParsePrimary();
   AstNode* ParseStringLiteral(bool allow_interpolation);
   String* ParseImportStringLiteral();
@@ skipping 168 matching lines @@
   bool unregister_pending_function_;
 
   LocalScope* async_temp_scope_;
 
   DISALLOW_COPY_AND_ASSIGN(Parser);
 };
 
 }  // namespace dart
 
 #endif  // VM_PARSER_H_