removed unused usings

src/VisualStudio/Core/Def/Implementation/AnalyzerDependency/AnalyzerFileWatcherService.cs

@@ -2,7 +2,6 @@
 
 using System;
 using System.Collections.Generic;
-using System.Collections.Immutable;
 using System.ComponentModel.Composition;
 using System.IO;
 using System.Linq;

src/VisualStudio/Core/Def/Implementation/AnalyzerDependency/IBindingRedirectionService.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 using Microsoft.CodeAnalysis;
 
 namespace Microsoft.VisualStudio.LanguageServices.Implementation