Revert "[io] exclude links from isDirectory()"

This reverts commit 49d743f.

Reason for revert: break vm-kernel-precomp-mac-release-simarm64 bot

Original change's description:
> [io] exclude links from isDirectory()
> 
> isDirectory() should not return true for links.
> 
> Bug: #35102
> Change-Id: I737345a581d6a50d7bccab0dbc10f1a31a57e219
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/121900
> Commit-Queue: Zichang Guo <zichangguo@google.com>
> Reviewed-by: Siva Annamalai <asiva@google.com>

TBR=asiva@google.com,zichangguo@google.com

Change-Id: I66ee7d3b3f0ae2bcf80b00e0f3c68bba3e520966
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: #35102
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/122060
Reviewed-by: Zichang Guo <zichangguo@google.com>
Commit-Queue: Zichang Guo <zichangguo@google.com>

Author: zichangg

sdk/lib/_internal/vm/bin/file_patch.dart

@@ -217,9 +217,7 @@ class _FileSystemWatcher {
         bool getIsDir(event) {
           if (Platform.isWindows) {
             // Windows does not get 'isDir' as part of the event.
-            // Links should also be skipped.
-            return FileSystemEntity.isDirectorySync(getPath(event)) &&
-                !FileSystemEntity.isLinkSync(getPath(event));
+            return FileSystemEntity.isDirectorySync(getPath(event));
           }
           return (event[0] & FileSystemEvent._isDir) != 0;
         }

sdk_nnbd/lib/_internal/vm/bin/file_patch.dart

@@ -219,9 +219,7 @@ class _FileSystemWatcher {
         bool getIsDir(event) {
           if (Platform.isWindows) {
             // Windows does not get 'isDir' as part of the event.
-            // Links should also be skipped.
-            return FileSystemEntity.isDirectorySync(getPath(event)) &&
-                !FileSystemEntity.isLinkSync(getPath(event));
+            return FileSystemEntity.isDirectorySync(getPath(event));
           }
           return (event[0] & FileSystemEvent._isDir) != 0;
         }

tests/standalone_2/io/link_test.dart

@@ -275,33 +275,10 @@ testRelativeLinksSync() {
   tempDirectory.deleteSync(recursive: true);
 }
 
-testIsDir() async {
-  Directory sandbox = Directory.systemTemp.createTempSync();
-  Directory dir = new Directory(sandbox.path + Platform.pathSeparator + "dir");
-  dir.createSync();
-  File target = new File(sandbox.path + Platform.pathSeparator + "target");
-  target.createSync();
-
-  final eventCompleter = new Completer<FileSystemEvent>();
-  var subscription;
-  subscription = dir.watch().listen((FileSystemEvent event) {
-    eventCompleter.complete(event);
-    subscription.cancel();
-  });
-  Link link = new Link(dir.path + Platform.pathSeparator + "link");
-  link.createSync(target.path);
-  final event = await eventCompleter.future;
-  // Link should not be marked as Dir.
-  Expect.isFalse(event.isDirectory);
-
-  sandbox.deleteSync(recursive: true);
-}
-
 main() {
   testCreateSync();
   testCreateLoopingLink();
   testRenameSync();
   testLinkErrorSync();
   testRelativeLinksSync();
-  testIsDir();
 }