Remove unused/unreferenced variables in codebase

src/Compilers/CSharp/Portable/Symbols/Source/SourceDelegateMethodSymbol.cs

@@ -16,7 +16,6 @@ internal abstract class SourceDelegateMethodSymbol : SourceMethodSymbol
     {
         private ImmutableArray<ParameterSymbol> _parameters;
         private readonly TypeSymbol _returnType;
-        private readonly RefKind _refKind;
 
         protected SourceDelegateMethodSymbol(
             SourceMemberContainerTypeSymbol delegateType,
@@ -36,8 +35,6 @@ protected void InitializeParameters(ImmutableArray<ParameterSymbol> parameters)
             _parameters = parameters;
         }
 
-        internal override RefKind RefKind => _refKind;
-
         internal static void AddDelegateMembers(
             SourceMemberContainerTypeSymbol delegateType,
             ArrayBuilder<Symbol> symbols,

src/Features/Core/Portable/Completion/CompletionServiceWithProviders.cs

@@ -86,7 +86,6 @@ protected virtual ImmutableArray<CompletionProvider> GetBuiltInProviders()
         }
 
         private ImmutableArray<CompletionProvider> _testProviders = ImmutableArray<CompletionProvider>.Empty;
-        private object p;
 
         internal void SetTestProviders(IEnumerable<CompletionProvider> testProviders)
         {

src/Features/Core/Portable/DocumentationComments/AbstractDocumentationCommentFormattingService.cs

@@ -11,9 +11,6 @@ namespace Microsoft.CodeAnalysis.DocumentationComments
 {
     internal abstract class AbstractDocumentationCommentFormattingService : IDocumentationCommentFormattingService
     {
-        private int _position;
-        private SemanticModel _semanticModel;
-
         private class FormatterState
         {
             private bool _anyNonWhitespaceSinceLastPara;

src/VisualStudio/CSharp/Impl/ProjectSystemShim/CSharpProjectShim.cs

@@ -38,7 +38,6 @@ internal abstract partial class CSharpProjectShim : AbstractLegacyProject
         private ICSharpProjectRoot _projectRoot;
 
         private OutputKind _outputKind = OutputKind.DynamicallyLinkedLibrary;
-        private Platform _platform = Platform.AnyCpu;
         private string _mainTypeName;
         private object[] _options = new object[(int)CompilerOptions.LARGEST_OPTION_ID];
 

src/VisualStudio/Core/Def/Packaging/PackageInstallerServiceFactory_UndoRedo.cs

@@ -51,6 +51,7 @@ private abstract class BaseUndoUnit : IOleUndoUnit
                 IOleUndoManager undoManager)
             {
                 this.packageInstallerService = packageInstallerService;
+                this.source = source;
                 this.packageName = packageName;
                 this.versionOpt = versionOpt;
                 this.dte = dte;

src/VisualStudio/Core/Impl/Options/AbstractRadioButtonViewModel.cs

@@ -13,7 +13,6 @@ internal abstract class AbstractRadioButtonViewModel : AbstractNotifyPropertyCha
         private readonly AbstractOptionPreviewViewModel _info;
         internal readonly string Preview;
         private bool _isChecked;
-        private string _groupName;
 
         public string Description { get; }
         public string GroupName { get; }