GetRuntimeCacheInfo.cs

private static void GetRuntimeCacheInfo(Type typeToTest)
{
    var expectedType = "System.RuntimeType";
    if (typeToTest.GetType().FullName != expectedType)
    {
        Console.WriteLine("  Unexpected type, Expected: {0}, Got: {1}", expectedType, typeToTest.GetType().FullName);
        return;                
    }

    Console.WriteLine("  Type: {0}", typeToTest.FullName);
    Console.WriteLine("  Reflection Type: {0} (BaseType: {1})", typeToTest.GetType(), typeToTest.GetType().BaseType);
    var runtimeTypeCache = typeToTest.GetType()
        .GetProperty("Cache", BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Static)
        .GetGetMethod(nonPublic: true)
        .Invoke(typeToTest, null);
    if (runtimeTypeCache.GetType().FullName != "System.RuntimeType+RuntimeTypeCache")
    {
        Console.WriteLine("  Unexpected type for 'Cache', Expected: {0}, Got: {1}", 
                          "System.RuntimeType+RuntimeTypeCache", runtimeTypeCache.GetType().FullName);
        return;
    }

    var fieldInfoCache = runtimeTypeCache.GetType()
        .GetField("m_fieldInfoCache", BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Static)
        .GetValue(runtimeTypeCache);
    if (fieldInfoCache == null)
    {
        Console.WriteLine("  m_fieldInfoCache is null, cache has not been initialised yet");
        return;
    }

    var isCacheComplete = fieldInfoCache.GetType()
        .GetField("m_cacheComplete", BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Static)
        .GetValue(fieldInfoCache);
    var members = fieldInfoCache.GetType()
        .GetField("m_allMembers", BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Static)
        .GetValue(fieldInfoCache) as Array;

    Console.WriteLine("  RuntimeTypeCache: {0}, m_cacheComplete = {1}, {2} items in cache", runtimeTypeCache, isCacheComplete, members.Length);
    for (int i = 0; i < members.Length; i++)
    {
        var item = members.GetValue(i);
        var fieldInfo = item as FieldInfo;
        Console.WriteLine("    [{0}] - {1} - {2}", i, item, String.Join(", ", fieldInfo?.Attributes));
    }
}