Fix operator== and hashCode for File and Folder objects.

pkg/analysis_server/lib/src/resource.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.
 
 library resource;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:io' as io;
 
@@ skipping 98 matching lines @@
  * An in-memory implementation of [Resource].
  */
 abstract class _MemoryResource implements Resource {
   final MemoryResourceProvider _provider;
   final String path;
 
   _MemoryResource(this._provider, this.path);
 
   @override
   bool operator ==(other) {
-    return identical(this, other);
+    if (runtimeType != other.runtimeType) {
+      return false;
+    }
+    return path == other.path;
   }
 
   @override
   bool get exists => _provider._pathToResource.containsKey(path);
 
   @override
   get hashCode => path.hashCode;
 
   @override
   String get shortName => posix.basename(path);
@@ skipping 359 matching lines @@
 
   _PhysicalResource(this._entry);
 
   @override
   bool get exists => _entry.existsSync();
 
   @override
   String get path => _entry.absolute.path;
 
   @override
-  get hashCode => _entry.hashCode;
+  get hashCode => path.hashCode;
+
+  @override
+  bool operator==(other) {
+    if (runtimeType != other.runtimeType) {
+      return false;
+    }
+    return path == other.path;
+  }
 
   @override
   String get shortName => basename(path);
 
   @override
   String toString() => path;
 
   @override
   Folder get parent {
     String parentPath = dirname(path);
@@ skipping 66 matching lines @@
   }
 
   /**
    * Return `true` if the given URI is a `file` URI.
    *
    * @param uri the URI being tested
    * @return `true` if the given URI is a `file` URI
    */
   static bool _isFileUri(Uri uri) => uri.scheme == _FILE_SCHEME;
 }