Report SX1101 violations as unnecessary code

Author: sharwell

StyleCop.Analyzers/StyleCop.Analyzers/ReadabilityRules/SX1101DoNotPrefixLocalMembersWithThis.cs

@@ -25,7 +25,7 @@ internal class SX1101DoNotPrefixLocalMembersWithThis : DiagnosticAnalyzer
         private static readonly string HelpLink = "https://github.com/DotNetAnalyzers/StyleCopAnalyzers/blob/master/documentation/SX1101.md";
 
         private static readonly DiagnosticDescriptor Descriptor =
-            new DiagnosticDescriptor(DiagnosticId, Title, MessageFormat, AnalyzerCategory.ReadabilityRules, DiagnosticSeverity.Warning, AnalyzerConstants.DisabledAlternative, Description, HelpLink);
+            new DiagnosticDescriptor(DiagnosticId, Title, MessageFormat, AnalyzerCategory.ReadabilityRules, DiagnosticSeverity.Warning, AnalyzerConstants.DisabledAlternative, Description, HelpLink, WellKnownDiagnosticTags.Unnecessary);
 
         private static readonly Action<CompilationStartAnalysisContext> CompilationStartAction = HandleCompilationStart;
         private static readonly Action<SyntaxNodeAnalysisContext> ThisExpressionAction = HandleThisExpression;