fix to run against latest analyzer

lib/src/codegen/ast_builder.dart

 // Copyright (c) 2015, 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.
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/src/dart/ast/token.dart';
 import 'package:analyzer/src/generated/utilities_dart.dart';
 import 'package:logging/logging.dart' as logger;
 
@@ skipping 507 matching lines @@
   static BlockFunctionBody blockFunctionBody(Block b) {
     return new BlockFunctionBody(null, null, b);
   }
 
   static ExpressionFunctionBody expressionFunctionBody(Expression body,
       [bool decl = false]) {
     Token semi = (decl) ? new Token(TokenType.SEMICOLON, 0) : null;
     return new ExpressionFunctionBody(null, null, body, semi);
   }
 
+  static ExpressionStatement expressionStatement(Expression expression) {
+    Token semi = new Token(TokenType.SEMICOLON, 0);
+    return new ExpressionStatement(expression, semi);
+  }
+
   static FunctionDeclaration functionDeclaration(
       TypeName rt, SimpleIdentifier f, FunctionExpression fexp) {
     return new FunctionDeclaration(null, null, null, rt, null, f, fexp);
   }
 
   static MethodDeclaration methodDeclaration(TypeName rt, SimpleIdentifier m,
       FormalParameterList fl, FunctionBody body,
       {bool isStatic: false}) {
     Token st = isStatic ? new KeywordToken(Keyword.STATIC, 0) : null;
     return new MethodDeclaration(
@@ skipping 47 matching lines @@
     Label l = new Label(s, new Token(TokenType.COLON, 0));
     return new NamedExpression(l, e);
   }
 
   static VariableDeclarationStatement variableDeclarationStatement(
       VariableDeclarationList varDecl) {
     var semi = new Token(TokenType.SEMICOLON, 0);
     return new VariableDeclarationStatement(varDecl, semi);
   }
 }