Re-enable ngen for desktop compiler builds (#6386)

* Re-enable ngen for desktop compilers

* Go even earlier

* Cooler mechanism

Author: KevinRansom

FSharpBuild.Directory.Build.targets

@@ -1,7 +1,7 @@
 <Project>
-
   <Import Project="Sdk.targets" Sdk="Microsoft.DotNet.Arcade.Sdk" />
   <Import Project="eng\targets\NuGet.targets" />
+  <Import Project="eng\targets\NGenBinaries.targets" />
   <Import Project="FSharp.Profiles.props" />
 
   <PropertyGroup Condition="'$(UseAssetTargetFallback)' == 'true'">

eng/targets/NGenBinaries.targets

@@ -0,0 +1,33 @@
+<Project>
+
+  <!-- Windows permissions means that users can't even see the directory $(SystemRoot)System32\config -->
+  <PropertyGroup Condition="'$(OS)' != 'Unix' AND Exists('$(SystemRoot)\System32\config\system')">
+    <IsAdministrator>true</IsAdministrator>
+    <DelaySign>true</DelaySign>
+    <PublicSign>false</PublicSign>
+  </PropertyGroup>
+
+  <Target Name="NGenWindowsBinaries"
+          AfterTargets="AfterBuild"
+          Condition="'$(OS)' != 'Unix' AND
+                     $(TargetFramework.StartsWith('net4')) AND 
+                     '$(NGenBinary)' == 'true' AND
+                     Exists('$(TargetPath)') ">
+    <PropertyGroup>
+      <PathToNGen64>$(windir)\Microsoft.NET\Framework64\v4.0.30319\ngen.exe</PathToNGen64>
+      <PathToNGen32>$(windir)\Microsoft.NET\Framework\v4.0.30319\ngen.exe</PathToNGen32>
+      <PathToSN32>$(WindowsSDK_ExecutablePath_x86)sn.exe</PathToSN32>
+    </PropertyGroup>
+
+    <!-- 
+        Enable Skip Verification and then NGen for both 32 and 64 bit product.
+        If compiling use the app config file, if present.
+    -->
+    <Exec Command='"$(PathToSN32)" /Vr "$(TargetPath)"' Condition = "Exists('$(PathToSN32)') AND Exists('$(TargetPath)') AND '$(IsAdministrator)' == 'true'"/>
+
+    <Exec Command='"$(PathToNGen64)" install "$(TargetPath)" /ExeConfig:$(TargetPath)' Condition = "Exists('$(PathToNGen64)') AND '$(PlatformTarget)' != 'x86' AND Exists('$(TargetPath).config') AND '$(IsAdministrator)' == 'true'"/>
+    <Exec Command='"$(PathToNGen32)" install "$(TargetPath)" /ExeConfig:$(TargetPath)' Condition = "Exists('$(PathToNGen32)') AND '$(PlatformTarget)' != 'x64' AND Exists('$(TargetPath).config') AND '$(IsAdministrator)' == 'true'"/>
+    <Exec Command='"$(PathToNGen64)" install "$(TargetPath)"' Condition = " Exists('$(PathToNGen64)') AND '$(PlatformTarget)' != 'x86' AND (!Exists('$(TargetPath).config')) AND '$(IsAdministrator)' == 'true' "/>
+    <Exec Command='"$(PathToNGen32)" install "$(TargetPath)"' Condition = " Exists('$(PathToNGen32)') AND '$(PlatformTarget)' != 'x64' AND (!Exists('$(TargetPath).config')) AND '$(IsAdministrator)' == 'true' "/>
+  </Target>
+</Project>

src/fsharp/fsiAnyCpu/fsiAnyCpu.fsproj

@@ -12,6 +12,7 @@
     <OtherFlags>$(OtherFlags)  --warnon:1182 --maxerrors:20 --extraoptimizationloops:1</OtherFlags>
     <Win32Resource>..\fsi\fsi.res</Win32Resource>
     <UseAssetTargetFallback>true</UseAssetTargetFallback>
+    <NGenBinary>true</NGenBinary>
   </PropertyGroup>
 
   <PropertyGroup>