Restore testassets during build to prevent timeouts

Fixes https://github.com/aspnet/AspNetCore-Internal/issues/1695

Author: pranavkm

src/Razor/Razor.Design/test/IntegrationTests/Microsoft.AspNetCore.Razor.Design.Test.csproj

@@ -32,6 +32,7 @@
     <Reference Include="Microsoft.AspNetCore.Razor.Design" />
     <Reference Include="rzc" />
     <Reference Include="Microsoft.AspNetCore.Razor.Test.MvcShim.ClassLib" />
+    <ProjectReference Include="..\testassets\RestoreTestProjects\RestoreTestProjects.csproj" ReferenceOutputAssembly="false" />
   </ItemGroup>
 
   <Target Name="GenerateBuildVariablesFile" BeforeTargets="BeforeBuild">

src/Razor/Razor.Design/test/testassets/RestoreTestProjects/RestoreTestProjects.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>netcoreapp2.1</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\AppWithP2PReference\AppWithP2PReference.csproj" ReferenceOutputAssembly="false" />
+    <ProjectReference Include="..\ClassLibrary\ClassLibrary.csproj" ReferenceOutputAssembly="false" />
+    <ProjectReference Include="..\ClassLibrary2\ClassLibrary2.csproj" ReferenceOutputAssembly="false" />
+    <ProjectReference Include="..\SimpleMvc\SimpleMvc.csproj" ReferenceOutputAssembly="false" />
+    <ProjectReference Include="..\SimpleMvcFSharp\SimpleMvcFSharp.fsproj" ReferenceOutputAssembly="false" />
+    <ProjectReference Include="..\SimplePages\SimplePages.csproj" ReferenceOutputAssembly="false" />
+  </ItemGroup>
+</Project>