Get ClrMethod from virtual method of struct

[Akeit0]

xoofx/JitBuddy#3

We can't get ClrMethod of TestStruct.Test by GetMethodByHandle.

interface ITest
{
    int Test();
}
struct TestStruct: ITest
{
    public int Test()
    {
        return 123;
    }
}

I think following behavior is related to this issue.

unsafe
{
    var fp =  typeof(TestStruct).GetMethod("Test")!.MethodHandle.GetFunctionPointer();
    delegate* <ITest, int> f = (delegate* <ITest, int>)fp;
    Console.WriteLine(f(new TestStruct()));//123
    TestDelegate testDelegate = typeof(TestStruct).GetMethod("Test")!.CreateDelegate<TestDelegate>();
    var testStruct = new TestStruct();
    Console.WriteLine(testDelegate(ref testStruct));//123
    var field =typeof(Delegate).GetField("_methodPtrAux", BindingFlags.NonPublic | BindingFlags.Instance);
    var methodPtr = (IntPtr)field.GetValue(testDelegate);
    
    Console.WriteLine((( delegate* <ref TestStruct, int>)methodPtr)(ref testStruct));
    field = typeof(Delegate).GetField("_methodPtr", BindingFlags.NonPublic | BindingFlags.Instance);
     methodPtr = (IntPtr)field.GetValue(testDelegate);
    
    Console.WriteLine(methodPtr ==  fp); //true
}