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

pkg/analysis_server/test/physical_resource_provider_test.dart

Index: pkg/analysis_server/test/physical_resource_provider_test.dart
diff --git a/pkg/analysis_server/test/physical_resource_provider_test.dart b/pkg/analysis_server/test/physical_resource_provider_test.dart
index a4b8a241ef1a1eaaf23d721365332cc78e6d48e9..47e75b9fda5fbb4fcbc1a54e92c139df237f275a 100644
--- a/pkg/analysis_server/test/physical_resource_provider_test.dart
+++ b/pkg/analysis_server/test/physical_resource_provider_test.dart
@@ -150,7 +150,15 @@ main() {
         });
 
         test('hashCode', () {
-          file.hashCode;
+          new io.File(path).writeAsStringSync('contents');
+          File file2 = PhysicalResourceProvider.INSTANCE.getResource(path);
+          expect(file.hashCode, equals(file2.hashCode));
+        });
+
+        test('equality', () {
+          new io.File(path).writeAsStringSync('contents');
+          File file2 = PhysicalResourceProvider.INSTANCE.getResource(path);
+          expect(file == file2, isTrue);
         });
 
         test('shortName', () {
@@ -178,6 +186,16 @@ main() {
           folder = PhysicalResourceProvider.INSTANCE.getResource(path);
         });
 
+        test('hashCode', () {
+          Folder folder2 = PhysicalResourceProvider.INSTANCE.getResource(path);
+          expect(folder.hashCode, equals(folder2.hashCode));
+        });
+
+        test('equality', () {
+          Folder folder2 = PhysicalResourceProvider.INSTANCE.getResource(path);
+          expect(folder == folder2, isTrue);
+        });
+
         group('getChild', () {
           test('does not exist', () {
             var child = folder.getChild('no-such-resource');