source-build: bundle NativeAOT libraries with the SDK.

This includes the libraries that are needed for source-built NativeAOT with the source-built SDK:
- runtime.<rid>.Microsoft.DotNet.ILCompiler extracted under 'packs'.
- Microsoft.DotNet.ILCompiler and Microsoft.NET.ILLink.Tasks as NuGet packages under 'library-packs'.

Author: tmds

src/Installer/redist-installer/targets/GenerateLayout.targets

@@ -202,6 +202,17 @@
         <RelativeLayoutPath>packs/%(PackageName)/%(PackageVersion)</RelativeLayoutPath>
       </BundledLayoutPackage>
 
+      <BundledLayoutPackage Include="MicrosoftDotNetILCompilerPackNupkg" Condition="'$(BundleNativeAotCompiler)' == 'true'">
+        <PackageName>runtime.$(SharedFrameworkRid).Microsoft.DotNet.ILCompiler</PackageName>
+        <PackageVersion>$(MicrosoftNETCoreAppRuntimePackageVersion)</PackageVersion>
+        <TargetFramework>$(TargetFramework)</TargetFramework>
+        <RelativeLayoutPath>packs/%(PackageName)/%(PackageVersion)</RelativeLayoutPath>
+      </BundledLayoutPackage>
+
+      <BundledLayoutLibraryPackage Include="$(SourceBuiltShippingPackagesDir)/../runtime/Microsoft.DotNet.ILCompiler.$(MicrosoftNETCoreAppRuntimePackageVersion).nupkg" Condition="'$(BundleNativeAotCompiler)' == 'true'" />
+
+      <BundledLayoutLibraryPackage Include="$(SourceBuiltShippingPackagesDir)/../runtime/Microsoft.NET.ILLink.Tasks.$(MicrosoftNETILLinkTasksPackageVersion).nupkg" Condition="'$(BundleNativeAotCompiler)' == 'true'" />
+
       <BundledInstallerComponent Include="DownloadedRuntimeDepsInstallerFile"
                                  Condition="('$(IsDebianBaseDistro)' == 'true' OR '$(IsRPMBasedDistro)' == 'true') And '$(SkipBuildingInstallers)' != 'true' And '$(InstallerExtension)' != '' And !$(Architecture.StartsWith('arm'))">
         <BaseUrl>$(NetRuntimeRootUrl)</BaseUrl>
@@ -460,6 +471,11 @@
           SkipUnchangedFiles="true"
           />
 
+    <Copy SourceFiles="@(BundledLayoutLibraryPackage)"
+          DestinationFolder="$(RedistLayoutPath)/library-packs"
+          SkipUnchangedFiles="true"
+          />
+
     <!-- From Version.targets in SDK redist -->
     <PropertyGroup>
       <ArtifactNameSdk>dotnet-toolset-internal</ArtifactNameSdk>

src/Tasks/Microsoft.NET.Build.Tasks/ProcessFrameworkReferences.cs

@@ -788,17 +788,22 @@ private ToolPackSupport AddToolPack(
 
                 var runtimePackName = packNamePattern.Replace("**RID**", hostRuntimeIdentifier);
 
-                if (EnableRuntimePackDownload)
+                var runtimePackItem = new TaskItem(runtimePackName);
+                runtimePackItem.SetMetadata(MetadataKeys.NuGetPackageId, runtimePackName);
+                runtimePackItem.SetMetadata(MetadataKeys.NuGetPackageVersion, packVersion);
+
+                string runtimePackPath = GetPackPath(runtimePackName, packVersion);
+                if (runtimePackPath != null)
+                {
+                    runtimePackItem.SetMetadata(MetadataKeys.PackageDirectory, runtimePackPath);
+                }
+                else if (EnableRuntimePackDownload)
                 {
                     // We need to download the runtime pack
                     runtimePackToDownload = new TaskItem(runtimePackName);
                     runtimePackToDownload.SetMetadata(MetadataKeys.Version, packVersion);
                 }
 
-                var runtimePackItem = new TaskItem(runtimePackName);
-                runtimePackItem.SetMetadata(MetadataKeys.NuGetPackageId, runtimePackName);
-                runtimePackItem.SetMetadata(MetadataKeys.NuGetPackageVersion, packVersion);
-
                 switch (toolPackType)
                 {
                     case ToolPackType.Crossgen2: