Correct sourcelink validation errors (#1033)

- problem noticed while investigating dotnet/aspnetcore-internal#3030
- make XAML files available where the compiler looks for them
  - enables the compiler to embed these files too

Directory.Build.props

@@ -14,7 +14,7 @@
   <Import
     Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), AspNetCoreSettings.props))\AspNetCoreSettings.props"
     Condition=" '$(CI)' != 'true' AND '$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), AspNetCoreSettings.props))' != '' " />
-  
+
   <PropertyGroup Label="Build Settings">
     <LangVersion>8.0</LangVersion>
     <StrongNameKeyId>MicrosoftAspNetCore</StrongNameKeyId>
@@ -24,6 +24,9 @@
     <GenerateResxSource>true</GenerateResxSource>
     <GenerateResxSourceEmitFormatMethods>true</GenerateResxSourceEmitFormatMethods>
     <ExcludeFromSourceBuild Condition="'$(IsUnitTestProject)' == 'true'">true</ExcludeFromSourceBuild>
+
+    <!-- Embed source files that are not tracked by the source control manager in the PDB. -->
+    <EmbedUntrackedSources>true</EmbedUntrackedSources>
   </PropertyGroup>
 
   <PropertyGroup Label="Package and Assembly Metadata">

src/Razor/src/RazorDeveloperTools/RazorDeveloperTools.csproj

@@ -100,10 +100,22 @@
     <PackageReference Include="Microsoft.VisualStudio.SDK.Analyzers" Version="$(MicrosoftVisualStudioSDKAnalyzersVersion)" PrivateAssets="all" />
   </ItemGroup>
 
-  <Target Name="_RemoveAnalyzers" BeforeTargets="CoreCompile">
+  <Target Name="_RemoveAnalyzers_CopyXaml" BeforeTargets="CoreCompile">
     <ItemGroup>
       <Analyzer Remove="@(Analyzer)" />
+      <_SourcesForXamlCopy Include="*\*.xaml" />
     </ItemGroup>
+
+    <!-- Make XAML files available to the compiler. This allows embedding the files for source link. -->
+    <Copy
+        SourceFiles="@(_SourcesForXamlCopy)"
+        DestinationFiles="@(_SourcesForXamlCopy -> '$(IntermediateOutputPath)%(RelativeDir)%(RelativeDir)%(Filename)%(Extension)')"
+        SkipUnchangedFiles="$(SkipCopyUnchangedFiles)"
+        OverwriteReadOnlyFiles="$(OverwriteReadOnlyFiles)"
+        Retries="$(CopyRetryCount)"
+        RetryDelayMilliseconds="$(CopyRetryDelayMilliseconds)"
+        UseHardlinksIfPossible="$(CreateHardLinksForCopyFilesToOutputDirectoryIfPossible)"
+        UseSymboliclinksIfPossible="$(CreateSymbolicLinksForCopyFilesToOutputDirectoryIfPossible)" />
   </Target>
 
   <Target Name="WORKAROUND_SETINFORMATIONVERSION" BeforeTargets="AddSourceRevisionToInformationalVersion">