#2286: Enable server-mode GC in ILSpy

This results in significant performance improvements when decompiling a project/solution, cutting the run-time in half.

ICSharpCode.Decompiler/ICSharpCode.Decompiler.csproj

@@ -643,10 +643,11 @@
     <Service Include="{508349b6-6b84-4df5-91f0-309beebad82d}" />
   </ItemGroup>
 
+  <ItemGroup>
+    <UpdateAssemblyInfoStamp Include="obj\update-assemblyinfo-last-commit-hash.txt" />
+  </ItemGroup>
+
   <Target Name="ILSpyUpdateAssemblyInfo" BeforeTargets="BeforeBuild">
-    <ItemGroup>
-      <UpdateAssemblyInfoStamp Include="obj\update-assemblyinfo-last-commit-hash.txt" />
-    </ItemGroup>
     <PropertyGroup Condition=" '$(OS)' == 'Windows_NT' ">
       <UpdateAssemblyInfo>powershell -NoProfile -ExecutionPolicy Bypass -File BuildTools/update-assemblyinfo.ps1 $(Configuration)</UpdateAssemblyInfo>
       <GitRevParse>git rev-parse HEAD^^{commit}</GitRevParse>
@@ -665,4 +666,8 @@
     <WriteLinesToFile Lines="$(CommitHash)" File="@(UpdateAssemblyInfoStamp)" Overwrite="true" Condition="'$(CommitHash)'!='$(LastCommitHash)'" />
   </Target>
 
+  <Target Name="CleanUpdateAssemblyInfo" BeforeTargets="BeforeClean">
+    <Delete Files="@(UpdateAssemblyInfoStamp)" />
+  </Target>
+
 </Project>

ILSpy/Properties/app.config.template

@@ -5,6 +5,7 @@
 	</startup>
 	<runtime>
 		<AppContextSwitchOverrides value="Switch.System.Windows.DoNotScaleForDpiChanges=false;Switch.System.IO.UseLegacyPathHandling=false;Switch.System.IO.BlockLongPaths=false" />
+		<gcServer enabled="true" />
 		<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
 			<!-- The redirects allow using AddIns with a different ILSpy version than they were compiled against. -->
 			<!-- No guarantee they'll work correctly, though (there might be breaking API changes in ILSpy). -->