Fix await parsing.

pkg/compiler/lib/src/scanner/parser.dart

 // 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.
 
 part of scanner;
 
 class FormalParameterType {
   final String type;
   const FormalParameterType(this.type);
   bool get isRequired => this == REQUIRED;
@@ skipping 23 matching lines @@
  *
  * Parse methods are generally named parseGrammarProductionSuffix. The
  * suffix can be one of "opt", or "star". "opt" means zero or one
  * matches, "star" means zero or more matches. For example,
  * [parseMetadataStar] corresponds to this grammar snippet: [:
  * metadata* :], and [parseTypeOpt] corresponds to: [: type? :].
  */
 class Parser {
   final Listener listener;
   bool mayParseFunctionExpressions = true;
-  bool yieldIsKeyword = false;
-  bool awaitIsKeyword = false;
+  bool yieldIsKeyword;
+  bool awaitIsKeyword;
 
-  Parser(this.listener);
+  Parser(this.listener,
+         {this.yieldIsKeyword: false, this.awaitIsKeyword: false});
 
   Token parseUnit(Token token) {
     listener.beginCompilationUnit(token);
     int count = 0;
     while (!identical(token.kind, EOF_TOKEN)) {
       token = parseTopLevelDeclaration(token);
       listener.endTopLevelDeclaration(token);
       count++;
     }
     listener.endCompilationUnit(count, token);
@@ skipping 2407 matching lines @@
       ++statementCount;
     }
     listener.endBlock(statementCount, begin, token);
     return expect('}', token);
   }
 
   Token parseAwaitExpression(Token token, bool allowCascades) {
     Token awaitToken = token;
     listener.beginAwaitExpression(awaitToken);
     token = expect('await', token);
-    token = parseUnaryExpression(token, allowCascades);
+    token = parsePrecedenceExpression(token, POSTFIX_PRECEDENCE,
+                                      allowCascades);
     listener.endAwaitExpression(awaitToken, token);
     return token;
   }
 
   Token parseThrowExpression(Token token, bool allowCascades) {
     Token throwToken = token;
     listener.beginThrowExpression(throwToken);
     token = expect('throw', token);
     token = allowCascades
         ? parseExpression(token)
@@ skipping 186 matching lines @@
     }
     listener.handleContinueStatement(hasTarget, continueKeyword, token);
     return expectSemicolon(token);
   }
 
   Token parseEmptyStatement(Token token) {
     listener.handleEmptyStatement(token);
     return expectSemicolon(token);
   }
 }