Making StyleCopTester take stylecop.json into account.

Fixes #2977

Author: vyrp

StyleCop.Analyzers/StyleCopTester/Program.cs

@@ -269,7 +269,7 @@ private static async Task<DocumentAnalyzerPerformance> TestDocumentPerformanceAs
                 var processedProject = project.WithCompilationOptions(modifiedCompilationOptions);
 
                 Compilation compilation = await processedProject.GetCompilationAsync(cancellationToken).ConfigureAwait(false);
-                CompilationWithAnalyzers compilationWithAnalyzers = compilation.WithAnalyzers(analyzers, new CompilationWithAnalyzersOptions(new AnalyzerOptions(ImmutableArray.Create<AdditionalText>()), null, true, false));
+                CompilationWithAnalyzers compilationWithAnalyzers = compilation.WithAnalyzers(analyzers, new CompilationWithAnalyzersOptions(processedProject.AnalyzerOptions, null, true, false));
 
                 SyntaxTree tree = await project.GetDocument(documentId).GetSyntaxTreeAsync(cancellationToken).ConfigureAwait(false);
                 await compilationWithAnalyzers.GetAnalyzerSyntaxDiagnosticsAsync(tree, cancellationToken).ConfigureAwait(false);
@@ -585,7 +585,7 @@ private static async Task<ImmutableArray<Diagnostic>> GetProjectAnalyzerDiagnost
             var processedProject = project.WithCompilationOptions(modifiedCompilationOptions);
 
             Compilation compilation = await processedProject.GetCompilationAsync(cancellationToken).ConfigureAwait(false);
-            CompilationWithAnalyzers compilationWithAnalyzers = compilation.WithAnalyzers(analyzers, new CompilationWithAnalyzersOptions(new AnalyzerOptions(ImmutableArray.Create<AdditionalText>()), null, true, false));
+            CompilationWithAnalyzers compilationWithAnalyzers = compilation.WithAnalyzers(analyzers, new CompilationWithAnalyzersOptions(processedProject.AnalyzerOptions, null, true, false));
 
             var diagnostics = await compilationWithAnalyzers.GetAllDiagnosticsAsync(cancellationToken).ConfigureAwait(false);
             return diagnostics;