Added StyleClassParser to Avalonia.Build.Tasks.

src/Avalonia.Build.Tasks/Avalonia.Build.Tasks.csproj

@@ -42,7 +42,10 @@
       <Compile Include="../Avalonia.Base/Utilities/IdentifierParser.cs">
         <Link>Markup/%(RecursiveDir)%(FileName)%(Extension)</Link>
       </Compile>
-      
+      <Compile Include="../Avalonia.Base/Utilities/StyleClassParser.cs">
+        <Link>Markup/%(RecursiveDir)%(FileName)%(Extension)</Link>
+      </Compile>
+
       <Compile Remove="../Markup/Avalonia.Markup.Xaml/XamlIl\xamlil.github\**\obj\**\*.cs" />
       <Compile Remove="../Markup/Avalonia.Markup.Xaml/XamlIl\xamlil.github\src\XamlIl\TypeSystem\SreTypeSystem.cs" />
       <PackageReference Include="Avalonia.Unofficial.Cecil" Version="20190417.2.0" PrivateAssets="All" />