Avoid unnecessary parsing/resolution when running command line analyzer.

pkg/analyzer/lib/src/generated/ast.dart

 // Copyright (c) 2014, 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.
 
 // This code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 
 library engine.ast;
 
 import 'dart:collection';
@@ skipping 11910 matching lines @@
       return propertyKeyword;
     } else if (operatorKeyword != null) {
       return operatorKeyword;
     }
     return _name.beginToken;
   }
 
   /**
    * Return `true` if this method is declared to be an abstract method.
    */
-  bool get isAbstract =>
-      externalKeyword == null && (_body is EmptyFunctionBody);
+  bool get isAbstract {
+    FunctionBody body = _body;
+    return externalKeyword == null &&
+        (body is EmptyFunctionBody && !body.semicolon.isSynthetic);
+  }
 
   /**
    * Return `true` if this method declares a getter.
    */
   bool get isGetter =>
       propertyKeyword != null &&
           (propertyKeyword as KeywordToken).keyword == Keyword.GET;
 
   /**
    * Return `true` if this method declares an operator.
@@ skipping 8173 matching lines @@
   }
 
   @override
   accept(AstVisitor visitor) => visitor.visitYieldStatement(this);
 
   @override
   void visitChildren(AstVisitor visitor) {
     _safelyVisitChild(_expression, visitor);
   }
 }