[DependencyInjection] introduce feature switch to disable S.R.E

docs/workflow/trimming/feature-switches.md

@@ -27,6 +27,7 @@ configurations but their defaults might vary as any SDK can set the defaults dif
 | MetadataUpdaterSupport | System.Reflection.Metadata.MetadataUpdater.IsSupported | Metadata update related code to be trimmed when set to false |
 | _EnableConsumingManagedCodeFromNativeHosting | System.Runtime.InteropServices.EnableConsumingManagedCodeFromNativeHosting | Getting a managed function from native hosting is disabled when set to false and related functionality can be trimmed. |
 | VerifyDependencyInjectionOpenGenericServiceTrimmability | Microsoft.Extensions.DependencyInjection.VerifyOpenGenericServiceTrimmability | When set to true, DependencyInjection will verify trimming annotations applied to open generic services are correct |
+| DisableDynamicEngine | Microsoft.Extensions.DependencyInjection.DisableDynamicEngine | When set to true, DependencyInjection will avoid using System.Reflection.Emit when realizing services |
 | NullabilityInfoContextSupport | System.Reflection.NullabilityInfoContext.IsSupported | Nullable attributes can be trimmed when set to false |
 | DynamicCodeSupport | System.Runtime.CompilerServices.RuntimeFeature.IsDynamicCodeSupported | Changes RuntimeFeature.IsDynamicCodeSupported to false to allow testing AOT-safe fallback code without publishing for Native AOT. |
 | _AggressiveAttributeTrimming | System.AggressiveAttributeTrimming | When set to true, aggressively trims attributes to allow for the most size savings possible, even if it could result in runtime behavior changes |

src/libraries/Microsoft.Extensions.DependencyInjection/src/ILLink/ILLink.Substitutions.xml

@@ -3,5 +3,8 @@
     <type fullname="Microsoft.Extensions.DependencyInjection.ServiceProvider">
       <method signature="System.Boolean get_VerifyOpenGenericServiceTrimmability()" body="stub" value="true" feature="Microsoft.Extensions.DependencyInjection.VerifyOpenGenericServiceTrimmability" featurevalue="true" />
     </type>
+    <type fullname="Microsoft.Extensions.DependencyInjection.ServiceProvider">
+      <method signature="System.Boolean get_DisableDynamicEngine()" body="stub" value="true" feature="Microsoft.Extensions.DependencyInjection.DisableDynamicEngine" featurevalue="true" />
+    </type>
   </assembly>
 </linker>

src/libraries/Microsoft.Extensions.DependencyInjection/src/ServiceProvider.cs

@@ -37,6 +37,9 @@ public sealed class ServiceProvider : IServiceProvider, IKeyedServiceProvider, I
         internal static bool VerifyOpenGenericServiceTrimmability { get; } =
             AppContext.TryGetSwitch("Microsoft.Extensions.DependencyInjection.VerifyOpenGenericServiceTrimmability", out bool verifyOpenGenerics) ? verifyOpenGenerics : false;
 
+        internal static bool DisableDynamicEngine { get; } =
+            AppContext.TryGetSwitch("Microsoft.Extensions.DependencyInjection.DisableDynamicEngine", out bool disableDynamicEngine) ? disableDynamicEngine : false;
+
         internal static bool VerifyAotCompatibility =>
 #if NETFRAMEWORK || NETSTANDARD2_0
             false;
@@ -246,7 +249,7 @@ private ServiceProviderEngine GetEngine()
 #if NETFRAMEWORK || NETSTANDARD2_0
             engine = CreateDynamicEngine();
 #else
-            if (RuntimeFeature.IsDynamicCodeCompiled)
+            if (RuntimeFeature.IsDynamicCodeCompiled && !DisableDynamicEngine)
             {
                 engine = CreateDynamicEngine();
             }