Compiling and executing code using anonymous types with VBCodeProvider fails

Using VBCodeProvider I am trying to compile and execute a block of VB code that performs a LINQ query and then processes the results. Two problems:

1. The code will not compile unless the anonymous types are declared as Object 

2. After declaring as Object the methods are not found.

I have searched high and low for a solution but found nothing of any use.


Code to Compile (embedded in project as string resource)
---------------



    Imports System.Linq
    Imports System.Collections.Generic
    Imports System

    public Class Y

    Friend Shared Function Result() as Integer

    Dim gts As List(Of GtDef) = {New GtDef(1, "FirstGte"), New GtDef(2, "FirstGte")}.Cast(Of GtDef).ToList

    Dim evts As List(Of EvDef) = {New EvDef(1, 1, "FirstEv"), New EvDef(2, 1, "SecondEv"), New EvDef(3, 2, "SecondEv")}.Cast(Of EvDef).ToList

    Dim x = From g In gts Join e In evts On g.ID Equals e.ParentID Group e By key = e.ParentID Into Group Select GtGroup = key, EvGroup = Group

    Dim sum As Integer = x.Count()

    For Each gte In x
      For Each evt In gte.EvGroup
        sum += evt.ID
      Next
    Next

    return sum

    End Function

    End Class


    Public Class GtDef

    Public ID As Integer
    Public Name As String

    Sub New(id As Integer, name As String)

        Me.ID = id
        Me.Name = name

    End Sub

    End Class

    Public Class EvDef

    Public ID As Integer
    Public ParentID As Integer
    Public Name As String

    Sub New(id As Integer, parentID As Integer, name As String)

         Me.ID = id
         Me.ParentID = parentID
         Me.Name = name

      End Sub

    End Class

Code used run compiler
----------------------


    Dim compiler As Compiler.CodeDomProvider = Nothing

    Dim provOptions As New Dictionary(Of String, String)
    provOptions.Add("CompilerVersion", "v4.0")

    compiler = New Microsoft.VisualBasic.VBCodeProvider(provOptions)

    Dim compilerParams As New Compiler.CompilerParameters()

    Dim assems As String() = AppDomain.CurrentDomain.GetAssemblies().Where(Function(find) Not find.IsDynamic).Select(Function(find) find.Location).ToArray
    compilerParams.ReferencedAssemblies.AddRange(assems)

    Dim compResults As Compiler.CompilerResults = compiler.CompileAssemblyFromSource(compilerParams, {My.Resources.Code})

    Dim cls As Type = compResults.CompiledAssembly.GetType("Y")
    cls.InvokeMember("Result", System.Reflection.BindingFlags.InvokeMethod Or System.Reflection.BindingFlags.NonPublic Or System.Reflection.BindingFlags.Static, Nothing, Nothing, Nothing)