Address PR feedback (#22466)

eng/Baseline.Designer.props

@@ -150,45 +150,6 @@
   <ItemGroup Condition=" '$(PackageId)' == 'Microsoft.AspNetCore.AzureAppServicesIntegration' AND '$(TargetFramework)' == 'netcoreapp3.1' ">
     <BaselinePackageReference Include="Microsoft.Extensions.Logging.AzureAppServices" Version="[3.1.4, )" />
   </ItemGroup>
-  <!-- Package: Microsoft.AspNetCore.Blazor-->
-  <PropertyGroup Condition=" '$(PackageId)' == 'Microsoft.AspNetCore.Blazor' ">
-    <BaselinePackageVersion>3.2.0-preview1.20073.1</BaselinePackageVersion>
-  </PropertyGroup>
-  <ItemGroup Condition=" '$(PackageId)' == 'Microsoft.AspNetCore.Blazor' AND '$(TargetFramework)' == 'netstandard2.1' ">
-    <BaselinePackageReference Include="Mono.WebAssembly.Interop" Version="[3.2.0-preview1.20073.1, )" />
-    <BaselinePackageReference Include="Microsoft.AspNetCore.Components.Web" Version="[3.1.0, )" />
-    <BaselinePackageReference Include="Microsoft.Extensions.Configuration" Version="[3.1.0, )" />
-  </ItemGroup>
-  <!-- Package: Microsoft.AspNetCore.Blazor.Build-->
-  <PropertyGroup Condition=" '$(PackageId)' == 'Microsoft.AspNetCore.Blazor.Build' ">
-    <BaselinePackageVersion>3.2.0-preview1.20073.1</BaselinePackageVersion>
-  </PropertyGroup>
-  <ItemGroup Condition=" '$(PackageId)' == 'Microsoft.AspNetCore.Blazor.Build' AND '$(TargetFramework)' == 'any' ">
-    <BaselinePackageReference Include="Microsoft.AspNetCore.Blazor.Mono" Version="[3.2.0-preview1.20067.1, )" />
-  </ItemGroup>
-  <!-- Package: Microsoft.AspNetCore.Blazor.DevServer-->
-  <PropertyGroup Condition=" '$(PackageId)' == 'Microsoft.AspNetCore.Blazor.DevServer' ">
-    <BaselinePackageVersion>3.2.0-preview1.20073.1</BaselinePackageVersion>
-  </PropertyGroup>
-  <!-- Package: Microsoft.AspNetCore.Blazor.HttpClient-->
-  <PropertyGroup Condition=" '$(PackageId)' == 'Microsoft.AspNetCore.Blazor.HttpClient' ">
-    <BaselinePackageVersion>3.2.0-preview1.20073.1</BaselinePackageVersion>
-  </PropertyGroup>
-  <ItemGroup Condition=" '$(PackageId)' == 'Microsoft.AspNetCore.Blazor.HttpClient' AND '$(TargetFramework)' == 'netstandard2.0' ">
-    <BaselinePackageReference Include="System.Text.Json" Version="[4.7.0, )" />
-  </ItemGroup>
-  <!-- Package: Microsoft.AspNetCore.Blazor.Server-->
-  <PropertyGroup Condition=" '$(PackageId)' == 'Microsoft.AspNetCore.Blazor.Server' ">
-    <BaselinePackageVersion>3.2.0-preview1.20073.1</BaselinePackageVersion>
-  </PropertyGroup>
-  <ItemGroup Condition=" '$(PackageId)' == 'Microsoft.AspNetCore.Blazor.Server' AND '$(TargetFramework)' == 'netcoreapp3.1' ">
-    <BaselinePackageReference Include="Mono.Cecil" Version="[0.10.1, )" />
-    <BaselinePackageReference Include="Newtonsoft.Json" Version="[12.0.2, )" />
-  </ItemGroup>
-  <!-- Package: Microsoft.AspNetCore.Blazor.Templates-->
-  <PropertyGroup Condition=" '$(PackageId)' == 'Microsoft.AspNetCore.Blazor.Templates' ">
-    <BaselinePackageVersion>3.2.0-preview1.20073.1</BaselinePackageVersion>
-  </PropertyGroup>
   <!-- Package: Microsoft.AspNetCore.Components-->
   <PropertyGroup Condition=" '$(PackageId)' == 'Microsoft.AspNetCore.Components' ">
     <BaselinePackageVersion>3.1.4</BaselinePackageVersion>

eng/Baseline.xml

@@ -26,12 +26,6 @@ Update this list when preparing for a new patch.
   <Package Id="Microsoft.AspNetCore.AzureAppServices.HostingStartup" Version="3.1.4" />
   <Package Id="Microsoft.AspNetCore.AzureAppServices.SiteExtension" Version="3.1.4" />
   <Package Id="Microsoft.AspNetCore.AzureAppServicesIntegration" Version="3.1.4" />
-  <Package Id="Microsoft.AspNetCore.Blazor" Version="3.2.0-preview1.20073.1" />
-  <Package Id="Microsoft.AspNetCore.Blazor.Build" Version="3.2.0-preview1.20073.1" />
-  <Package Id="Microsoft.AspNetCore.Blazor.DevServer" Version="3.2.0-preview1.20073.1" />
-  <Package Id="Microsoft.AspNetCore.Blazor.HttpClient" Version="3.2.0-preview1.20073.1" />
-  <Package Id="Microsoft.AspNetCore.Blazor.Server" Version="3.2.0-preview1.20073.1" />
-  <Package Id="Microsoft.AspNetCore.Blazor.Templates" Version="3.2.0-preview1.20073.1" />
   <Package Id="Microsoft.AspNetCore.Components" Version="3.1.4" />
   <Package Id="Microsoft.AspNetCore.Components.Analyzers" Version="3.1.4" />
   <Package Id="Microsoft.AspNetCore.Components.Authorization" Version="3.1.4" />

eng/targets/CSharp.Common.targets

@@ -29,6 +29,12 @@
   </Target>
 
   <Choose>
+    <!--
+        C# 8.0's nullable annotations only work for .NET Core 3.0+ by default. However it can be made to work for other target frameworks
+        by compiling the annotations (as internal types).
+        The code block that follows sets it up so projects in this repo that target ns2.0 or netfx can compile when Nullable is configured.
+        Based on https://github.com/dotnet/runtime/blob/93b6c449d4f31ddd7d573d1d3769e681d5ebceb9/src/libraries/Directory.Build.targets#L215-L222
+     -->
     <When Condition="'$(Nullable)' != '' AND ('$(TargetFramework)' == 'netstandard2.0' OR '$(TargetFrameworkIdentifier)' == '.NETFramework')">
         <PropertyGroup>
           <DefineConstants>$(DefineConstants),INTERNAL_NULLABLE_ATTRIBUTES</DefineConstants>