rearrange ObjectFieldAccessor

Author: SergeiPavlov

Orm/Xtensive.Orm/Tuples/Packed/TupleLayout.cs

@@ -52,6 +52,8 @@ internal static class ValueFieldAccessorResolver
       private static readonly ValueFieldAccessor GuidAccessor = new GuidFieldAccessor();
       private static readonly ValueFieldAccessor DateTimeOffsetAccessor = new DateTimeOffsetFieldAccessor();
 
+      private static readonly ObjectFieldAccessor ObjectAccessor = new();
+
       private sealed class TypeReferenceEqualityComparer : IEqualityComparer<Type>
       {
         public static readonly TypeReferenceEqualityComparer Instance = new();
@@ -99,8 +101,6 @@ private sealed class TypeReferenceEqualityComparer : IEqualityComparer<Type>
         [WellKnownTypes.NullableUInt64] = UInt64Accessor
       };
 
-      private static readonly ObjectFieldAccessor ObjectAccessor = new ObjectFieldAccessor();
-
       private static readonly int NullableTypeMetadataToken = WellKnownTypes.NullableOfT.MetadataToken;
 
       public static ValueFieldAccessor GetValue(Type probeType) =>