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Cannot translate nested anonymous type

See original GitHub issue

Cannot translate

{ count = new { count = ctx.OrderItems.Where(orderItem => Order.Id == orderItem.OrderId).Count() } }

Exception message: System.NullReferenceException: 'Object reference not set to an instance of an object.'
Stack trace:
This exception was originally thrown at this call stack:
    LinqToDB.Linq.Builder.ExpressionBuilder.EnforceServerSide(LinqToDB.Linq.Builder.IBuildContext)
    LinqToDB.Linq.Builder.ExpressionBuilder.TransformExpression(LinqToDB.Linq.Builder.IBuildContext, System.Linq.Expressions.Expression, bool, string)
    LinqToDB.Linq.Builder.ExpressionBuilder.BuildExpression.AnonymousMethod__0(System.Linq.Expressions.Expression)
    LinqToDB.Expressions.Extensions.Transform(System.Linq.Expressions.Expression, System.Func<System.Linq.Expressions.Expression, LinqToDB.Expressions.TransformInfo>)
    LinqToDB.Linq.Builder.ExpressionBuilder.BuildExpression(LinqToDB.Linq.Builder.IBuildContext, System.Linq.Expressions.Expression, bool, string)
    LinqToDB.Linq.Builder.SelectContext.BuildExpression.AnonymousMethod__2(System.Linq.Expressions.Expression)
    LinqToDB.Expressions.Extensions.Transform(System.Linq.Expressions.Expression, System.Func<System.Linq.Expressions.Expression, System.Linq.Expressions.Expression>)
    LinqToDB.Expressions.Extensions.TransformX(System.Linq.Expressions.BinaryExpression, System.Func<System.Linq.Expressions.Expression, System.Linq.Expressions.Expression>)
    LinqToDB.Expressions.Extensions.Transform(System.Linq.Expressions.Expression, System.Func<System.Linq.Expressions.Expression, System.Linq.Expressions.Expression>)
    LinqToDB.Expressions.Extensions.TransformX(System.Linq.Expressions.LambdaExpression, System.Func<System.Linq.Expressions.Expression, System.Linq.Expressions.Expression>)
    ...
    [Call Stack Truncated]

Steps to reproduce

using LinqToDB;
using LinqToDB.Mapping;
using System.Linq;

namespace OdataToEntity.Test.Linq2Db
{
    [Table(Schema = "dbo", Name = "Orders")]
    public class Order
    {
        [PrimaryKey, Identity] public int Id { get; set; }
        [Column, NotNull] public int CustomerId { get; set; }
    }

    [Table(Schema = "dbo", Name = "Customers")]
    public class Customer
    {
        [PrimaryKey, Identity] public int Id { get; set; }
    }

    [Table(Schema = "dbo", Name = "OrderItems")]
    public class OrderItem
    {
        [PrimaryKey, Identity] public int Id { get; set; }
        [Column, NotNull] public int OrderId { get; set; }
    }

    public partial class OdataToEntityDB : LinqToDB.Data.DataConnection
    {
        public OdataToEntityDB()
            : base("Microsoft.Data.SqlClient", @"Server=.\sqlexpress;Initial Catalog=OdataToEntity;Trusted_Connection=Yes;")
        {
        }

        public ITable<Customer> Customers { get { return this.GetTable<Customer>(); } }
        public ITable<Order> Orders { get { return this.GetTable<Order>(); } }
        public ITable<OrderItem> OrderItems { get { return this.GetTable<OrderItem>(); } }
    }

    class Program
    {
        static void Main()
        {
            using var ctx = new OdataToEntityDB();
            ctx.Orders
                .Select(
                    Order => new
                    {
                        Order,
                        count = new { count = ctx.OrderItems.Where(orderItem => Order.Id == orderItem.OrderId).Count() }
                    })
                .GroupJoin(
                    ctx.Customers,
                    order => order.Order.CustomerId,
                    customer => customer.Id,
                    (order, customer) => new { order, customer })
                .SelectMany(
                    a => a.customer.DefaultIfEmpty(),
                    (order, customer) => new { order.order.Order, order.order.count, customer }).ToList();
        }
    }
}

Environment details

linq2db version: 3.3.0 Database Server: SqlServer Express 14.0 Database Provider: Microsoft.Data.SqlClient Operating system: Windows Pro 20H2 .NET Framework: 5.0.300