Disable more FileSystemWatcher tests on OSX

Turns out my previous run of the OSX tests wasn't actually running all tests, due to my having an outdated xunit.netcore.extensions.dll and xunit silently not running some tests as a result.

@sokket is investigating.  In the meantime, I'm disabling the rest of these on OSX.

Author: stephentoub

src/System.IO.FileSystem.Watcher/tests/FileSystemWatcher.NotifyFilter.cs

@@ -10,6 +10,7 @@
 public partial class FileSystemWatcher_4000_Tests
 {
     [Fact]
+    [ActiveIssue(2011, PlatformID.OSX)]
     public static void FileSystemWatcher_NotifyFilter_Attributes()
     {
         using (var file = Utility.CreateTestFile())
@@ -32,6 +33,7 @@ public static void FileSystemWatcher_NotifyFilter_Attributes()
 
     [Fact]
     [PlatformSpecific(PlatformID.Windows | PlatformID.OSX)]
+    [ActiveIssue(2011, PlatformID.OSX)]
     public static void FileSystemWatcher_NotifyFilter_CreationTime()
     {
         using (var file = Utility.CreateTestFile())
@@ -92,6 +94,7 @@ public static void FileSystemWatcher_NotifyFilter_FileName()
     }
 
     [Fact]
+    [ActiveIssue(2011, PlatformID.OSX)]
     public static void FileSystemWatcher_NotifyFilter_LastAccessTime()
     {
         using (var file = Utility.CreateTestFile())
@@ -110,6 +113,7 @@ public static void FileSystemWatcher_NotifyFilter_LastAccessTime()
     }
 
     [Fact]
+    [ActiveIssue(2011, PlatformID.OSX)]
     public static void FileSystemWatcher_NotifyFilter_LastWriteTime()
     {
         using (var file = Utility.CreateTestFile())
@@ -128,6 +132,7 @@ public static void FileSystemWatcher_NotifyFilter_LastWriteTime()
     }
 
     [Fact]
+    [ActiveIssue(2011, PlatformID.OSX)]
     public static void FileSystemWatcher_NotifyFilter_Size()
     {
         using (var file = Utility.CreateTestFile())
@@ -198,6 +203,7 @@ public static void FileSystemWatcher_NotifyFilter_Security()
 
 
     [Fact]
+    [ActiveIssue(2011, PlatformID.OSX)]
     public static void FileSystemWatcher_NotifyFilter_Negative()
     {
         using (var file = Utility.CreateTestFile())