Adapt GetILSpyPath and copy both x64 and arm64 ILSpy into the VSIX for VS 2022

ILSpy.AddIn.Shared/Commands/OpenILSpyCommand.cs

@@ -47,12 +47,6 @@ namespace ICSharpCode.ILSpy.AddIn.Commands
 
 		protected abstract void OnExecute(object sender, EventArgs e);
 
-		protected string GetILSpyPath()
-		{
-			var basePath = Path.GetDirectoryName(typeof(ILSpyAddInPackage).Assembly.Location);
-			return Path.Combine(basePath, "ILSpy", "ILSpy.exe");
-		}
-
 		protected void OpenAssembliesInILSpy(ILSpyParameters parameters)
 		{
 			ThreadHelper.ThrowIfNotOnUIThread();

ILSpy.AddIn.Shared/ILSpyInstance.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
 using System.Linq;
+using System.Runtime.InteropServices;
 using System.Text;
 using System.Threading.Tasks;
 
@@ -31,8 +32,15 @@ namespace ICSharpCode.ILSpy.AddIn
 
 		static string GetILSpyPath()
 		{
+			// Only VS2022 supports arm64, so we can gloss over 2017-2019 support
+			string archPathSegment = "x64";
+			if (RuntimeInformation.ProcessArchitecture == Architecture.Arm64)
+			{
+				archPathSegment = "arm64";
+			}
+
 			var basePath = Path.GetDirectoryName(typeof(ILSpyAddInPackage).Assembly.Location);
-			return Path.Combine(basePath, "ILSpy", "ILSpy.exe");
+			return Path.Combine(basePath, archPathSegment, "ILSpy", "ILSpy.exe");
 		}
 
 		public void Start()

ILSpy.AddIn.VS2022/ILSpy.AddIn.VS2022.csproj

@@ -74,16 +74,23 @@
   </ItemGroup>
 
   <PropertyGroup>
-    <ILSpyBuildPath>..\ILSpy\bin\$(Configuration)\net6.0-windows\win-x64\publish\fwdependent\</ILSpyBuildPath>
+    <ILSpyBuildPathX64>..\ILSpy\bin\$(Configuration)\net6.0-windows\win-x64\publish\fwdependent\</ILSpyBuildPathX64>
+    <ILSpyBuildPathArm64>..\ILSpy\bin\$(Configuration)\net6.0-windows\win-arm64\publish\fwdependent\</ILSpyBuildPathArm64>
   </PropertyGroup>
 
   <Target Name="IncludeILSpyDistributionInVSIXSubFolder" AfterTargets="ResolveProjectReferences">
     <ItemGroup>
-      <VSIXSourceItem Include="$(ILSpyBuildPath)zh-Hans\ILSpy.resources.dll;$(ILSpyBuildPath)zh-Hans\ILSpy.ReadyToRun.Plugin.resources.dll;">
+      <VSIXSourceItem Include="$(ILSpyBuildPathX64)zh-Hans\ILSpy.resources.dll;$(ILSpyBuildPathX64)zh-Hans\ILSpy.ReadyToRun.Plugin.resources.dll;">
-        <VSIXSubPath>\ILSpy\zh-Hans\</VSIXSubPath>
+        <VSIXSubPath>\x64\ILSpy\zh-Hans\</VSIXSubPath>
       </VSIXSourceItem>
-      <VSIXSourceItem Include="$(ILSpyBuildPath)*.dll;$(ILSpyBuildPath)ILSpy.exe;$(ILSpyBuildPath)*.json">
+      <VSIXSourceItem Include="$(ILSpyBuildPathX64)*.dll;$(ILSpyBuildPathX64)ILSpy.exe;$(ILSpyBuildPathX64)*.json">
-        <VSIXSubPath>\ILSpy</VSIXSubPath>
+        <VSIXSubPath>\x64\ILSpy</VSIXSubPath>
+      </VSIXSourceItem>
+      <VSIXSourceItem Include="$(ILSpyBuildPathArm64)zh-Hans\ILSpy.resources.dll;$(ILSpyBuildPathArm64)zh-Hans\ILSpy.ReadyToRun.Plugin.resources.dll;">
+        <VSIXSubPath>\arm64\ILSpy\zh-Hans\</VSIXSubPath>
+      </VSIXSourceItem>
+      <VSIXSourceItem Include="$(ILSpyBuildPathArm64)*.dll;$(ILSpyBuildPathArm64)ILSpy.exe;$(ILSpyBuildPathArm64)*.json">
+        <VSIXSubPath>\arm64\ILSpy</VSIXSubPath>
       </VSIXSourceItem>
     </ItemGroup>
   </Target>