Revert "Add where T : allows ref struct anti-constraints."

This reverts commit 2d46b79.

Author: timcassell

src/BenchmarkDotNet/Engines/DeadCodeEliminationHelper.cs

@@ -11,23 +11,15 @@ public static class DeadCodeEliminationHelper
         /// </summary>
         [MethodImpl(MethodImplOptions.NoInlining)]
         [UsedImplicitly] // Used in generated benchmarks
-        public static void KeepAliveWithoutBoxing<T>(T value)
-#if NET9_0_OR_GREATER
-            where T : allows ref struct
-#endif
-        { }
+        public static void KeepAliveWithoutBoxing<T>(T value) { }
 
         /// <summary>
         /// This method can't get inlined, so any value send to it
         /// will not get eliminated by the dead code elimination
         /// </summary>
         [MethodImpl(MethodImplOptions.NoInlining)]
         [UsedImplicitly] // Used in generated benchmarks
-        public static void KeepAliveWithoutBoxing<T>(ref T value)
-#if NET9_0_OR_GREATER
-            where T : allows ref struct
-#endif
-        { }
+        public static void KeepAliveWithoutBoxing<T>(ref T value) { }
 
         /// <summary>
         /// This method can't get inlined, so any value send to it
@@ -36,10 +28,6 @@ public static void KeepAliveWithoutBoxing<T>(ref T value)
         /// </summary>
         [MethodImpl(MethodImplOptions.NoInlining)]
         [UsedImplicitly] // Used in generated benchmarks
-        public static void KeepAliveWithoutBoxingReadonly<T>(in T value)
-#if NET9_0_OR_GREATER
-            where T : allows ref struct
-#endif
-        { }
+        public static void KeepAliveWithoutBoxingReadonly<T>(in T value) { }
     }
 }

src/BenchmarkDotNet/Toolchains/InProcess/NoEmit/BenchmarkActionImpl.cs

@@ -544,21 +544,18 @@ public override void Cleanup()
 }
 
 [AggressivelyOptimizeMethods]
-public class BenchmarkActionAsyncEnumerable<T> : BenchmarkActionBase
-#if NET9_0_OR_GREATER
-    where T : allows ref struct
-#endif
+public class BenchmarkActionConfiguredCancelableAsyncEnumerable<T> : BenchmarkActionBase
 {
-    private readonly Func<IAsyncEnumerable<T>> callback;
+    private readonly Func<ConfiguredCancelableAsyncEnumerable<T>> callback;
     private readonly int unrollFactor;
     private WorkloadValueTaskSource workloadValueTaskSource = null!;
     private IClock? clock;
     private long invokeCount;
 
     [SetsRequiredMembers]
-    public BenchmarkActionAsyncEnumerable(object? instance, MethodInfo method, int unrollFactor)
+    public BenchmarkActionConfiguredCancelableAsyncEnumerable(object? instance, MethodInfo method, int unrollFactor)
     {
-        callback = CreateWorkload<Func<IAsyncEnumerable<T>>>(instance, method);
+        callback = CreateWorkload<Func<ConfiguredCancelableAsyncEnumerable<T>>>(instance, method);
         this.unrollFactor = unrollFactor;
         InvokeSingle = InvokeOnce;
         InvokeUnroll = WorkloadActionUnroll;
@@ -626,21 +623,18 @@ public override void Cleanup()
 }
 
 [AggressivelyOptimizeMethods]
-public class BenchmarkActionConfiguredCancelableAsyncEnumerable<T> : BenchmarkActionBase
-#if NET10_0_OR_GREATER
-    where T : allows ref struct
-#endif
+public class BenchmarkActionAsyncEnumerable<T> : BenchmarkActionBase
 {
-    private readonly Func<ConfiguredCancelableAsyncEnumerable<T>> callback;
+    private readonly Func<IAsyncEnumerable<T>> callback;
     private readonly int unrollFactor;
     private WorkloadValueTaskSource workloadValueTaskSource = null!;
     private IClock? clock;
     private long invokeCount;
 
     [SetsRequiredMembers]
-    public BenchmarkActionConfiguredCancelableAsyncEnumerable(object? instance, MethodInfo method, int unrollFactor)
+    public BenchmarkActionAsyncEnumerable(object? instance, MethodInfo method, int unrollFactor)
     {
-        callback = CreateWorkload<Func<ConfiguredCancelableAsyncEnumerable<T>>>(instance, method);
+        callback = CreateWorkload<Func<IAsyncEnumerable<T>>>(instance, method);
         this.unrollFactor = unrollFactor;
         InvokeSingle = InvokeOnce;
         InvokeUnroll = WorkloadActionUnroll;