Go direct to ValueStore for untyped GetValue.

Avoids a virtual call in the case of styled properties.

src/Avalonia.Base/AvaloniaObject.cs

@@ -206,7 +206,15 @@ namespace Avalonia
         /// </summary>
         /// <param name="property">The property.</param>
         /// <returns>The value.</returns>
-        public object? GetValue(AvaloniaProperty property) => property.RouteGetValue(this);
+        public object? GetValue(AvaloniaProperty property)
+        {
+            _ = property ?? throw new ArgumentNullException(nameof(property));
+
+            if (property.IsDirect)
+                return property.RouteGetValue(this);
+            else
+                return _values.GetValue(property);
+        }
 
         /// <summary>
         /// Gets a <see cref="AvaloniaProperty"/> value.

src/Avalonia.Base/PropertyStore/ValueStore.cs

@@ -2,12 +2,10 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
-using Avalonia.Collections.Pooled;
 using Avalonia.Data;
 using Avalonia.Diagnostics;
 using Avalonia.Logging;
 using Avalonia.Utilities;
-using JetBrains.Annotations;
 
 namespace Avalonia.PropertyStore
 {