Add FxCop to the build

Author: Numpsy

src/ICSharpCode.SharpZipLib/ICSharpCode.SharpZipLib.csproj

@@ -31,6 +31,10 @@ Please see https://github.com/icsharpcode/SharpZipLib/wiki/Release-1.2 for more
   </PropertyGroup>
 
 	<ItemGroup>
+		<PackageReference Include="Microsoft.CodeAnalysis.FxCopAnalyzers" Version="2.9.8">
+		  <PrivateAssets>all</PrivateAssets>
+		  <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+		</PackageReference>
 		<PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
 	</ItemGroup>