Use helpers from Microsoft.CodeAnalysis.Testing

* DiagnosticResult
* EmptyCodeFixProvider
* MetadataReferences
* SourceFileCollection
* SourceFileList

Author: sharwell

NuGet.config

@@ -2,6 +2,7 @@
 <configuration>
   <packageSources>
     <add key="roslyn" value="https://dotnet.myget.org/F/roslyn/api/v3/index.json" />
+    <add key="roslyn-analyzers" value="https://dotnet.myget.org/F/roslyn-analyzers/api/v3/index.json" />
     <add key="symreader-converter" value="https://dotnet.myget.org/F/symreader-converter/api/v3/index.json" />
   </packageSources>
 </configuration>

StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp7/LayoutRules/SA1500CSharp7UnitTests.cs

@@ -5,6 +5,7 @@ namespace StyleCop.Analyzers.Test.CSharp7.LayoutRules
 {
     using System.Threading;
     using System.Threading.Tasks;
+    using Microsoft.CodeAnalysis.Testing;
     using StyleCop.Analyzers.Test.LayoutRules;
     using TestHelper;
     using Xunit;

StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp7/LayoutRules/SA1509CSharp7UnitTests.cs

@@ -5,6 +5,7 @@ namespace StyleCop.Analyzers.Test.CSharp7.LayoutRules
 {
     using System.Threading;
     using System.Threading.Tasks;
+    using Microsoft.CodeAnalysis.Testing;
     using StyleCop.Analyzers.Test.LayoutRules;
     using TestHelper;
     using Xunit;

StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp7/MaintainabilityRules/SA1119CSharp7UnitTests.cs

@@ -5,6 +5,7 @@ namespace StyleCop.Analyzers.Test.CSharp7.MaintainabilityRules
 {
     using System.Threading;
     using System.Threading.Tasks;
+    using Microsoft.CodeAnalysis.Testing;
     using StyleCop.Analyzers.Test.MaintainabilityRules;
     using TestHelper;
     using Xunit;

StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp7/NamingRules/SA1300CSharp7UnitTests.cs

@@ -5,6 +5,7 @@ namespace StyleCop.Analyzers.Test.CSharp7.NamingRules
 {
     using System.Threading;
     using System.Threading.Tasks;
+    using Microsoft.CodeAnalysis.Testing;
     using StyleCop.Analyzers.Test.NamingRules;
     using TestHelper;
     using Xunit;

StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp7/NamingRules/SA1305CSharp7UnitTests.cs

@@ -5,6 +5,7 @@ namespace StyleCop.Analyzers.Test.CSharp7.NamingRules
 {
     using System.Threading;
     using System.Threading.Tasks;
+    using Microsoft.CodeAnalysis.Testing;
     using StyleCop.Analyzers.Test.NamingRules;
     using TestHelper;
     using Xunit;

StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp7/NamingRules/SA1312CSharp7UnitTests.cs

@@ -5,6 +5,7 @@ namespace StyleCop.Analyzers.Test.CSharp7.NamingRules
 {
     using System.Threading;
     using System.Threading.Tasks;
+    using Microsoft.CodeAnalysis.Testing;
     using StyleCop.Analyzers.Test.NamingRules;
     using TestHelper;
     using Xunit;

StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp7/OrderingRules/SA1206CSharp7UnitTests.cs

@@ -6,6 +6,7 @@ namespace StyleCop.Analyzers.Test.CSharp7.OrderingRules
     using System.Threading;
     using System.Threading.Tasks;
     using Microsoft.CodeAnalysis.CSharp;
+    using Microsoft.CodeAnalysis.Testing;
     using StyleCop.Analyzers.OrderingRules;
     using StyleCop.Analyzers.Test.OrderingRules;
     using StyleCop.Analyzers.Test.Verifiers;

StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp7/ReadabilityRules/SA1110CSharp7UnitTests.cs

@@ -5,6 +5,7 @@ namespace StyleCop.Analyzers.Test.CSharp7.ReadabilityRules
 {
     using System.Threading;
     using System.Threading.Tasks;
+    using Microsoft.CodeAnalysis.Testing;
     using StyleCop.Analyzers.Test.ReadabilityRules;
     using TestHelper;
     using Xunit;

StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp7/ReadabilityRules/SA1111CSharp7UnitTests.cs

@@ -5,6 +5,7 @@ namespace StyleCop.Analyzers.Test.CSharp7.ReadabilityRules
 {
     using System.Threading;
     using System.Threading.Tasks;
+    using Microsoft.CodeAnalysis.Testing;
     using StyleCop.Analyzers.Test.ReadabilityRules;
     using TestHelper;
     using Xunit;