Add support for analyzing individual URIs.

pkg/compiler/lib/src/elements/elements.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.
 
 library elements;
 
 import '../compiler.dart' show
     Compiler,
     isPrivateName;
 import '../constants/constructors.dart';
@@ skipping 1558 matching lines @@
   /// [TreeElements]. This is not available if [hasResolvedAst] is `false`.
   ResolvedAst get resolvedAst;
 }
 
 class ResolvedAst {
   final Element element;
   final Node node;
   final TreeElements elements;
 
   ResolvedAst(this.element, this.node, this.elements);
+
+  String toString() => '$element:$node';
 }
 
 /// A [MemberSignature] is a member of an interface.
 ///
 /// A signature is either a method or a getter or setter, possibly implicitly
 /// defined by a field declarations. Fields themselves are not members of an
 /// interface.
 ///
 /// A [MemberSignature] may be defined by a member declaration or may be
 /// synthetized from a set of declarations.
@@ skipping 62 matching lines @@
   bool get isDeclaredByField;
 
   /// Returns `true` if this member is abstract.
   bool get isAbstract;
 
   /// If abstract, [implementation] points to the overridden concrete member,
   /// if any. Otherwise [implementation] points to the member itself.
   Member get implementation;
 }