runtime: ICorDebugManagedCallback::DebuggerError when unloading AssemblyLoadContext

Running the following code in VS d16.5 typically fails with an error dialog due to the CLR’s debugging interfaces returning DebuggerError with the error set to E_INVALIDARG.

using System;
using System.Diagnostics;
using System.IO;
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Runtime.Loader;

namespace PlugInTest
{
    class Program
    {
        //TODO: insert absolute path to managed dll
        static string pluginPath = @"C:\MyPlugin.dll";
        static AssemblyLoadContext AssemblyLoadContext;
        static Assembly Assembly;

        [MethodImpl(MethodImplOptions.NoInlining)]
        private static void Load()
        {
            AssemblyLoadContext = new AssemblyLoadContext("PluginLoader", true);
            Assembly = AssemblyLoadContext.LoadFromAssemblyPath(pluginPath);
        }

        [MethodImpl(MethodImplOptions.NoInlining)]
        private static WeakReference Unload()
        {
            Assembly = null;
            AssemblyLoadContext.Unload();
            WeakReference weakRef = new WeakReference(AssemblyLoadContext);
            AssemblyLoadContext = null;
            return weakRef;
        }

        [MethodImpl(MethodImplOptions.NoInlining)]
        private static void Test()
        {
            WeakReference weakRef;
            {
                Load();
                weakRef = Unload();
            }

            while (weakRef.IsAlive)
            {
                GC.Collect();
                GC.WaitForPendingFinalizers();
            }
            Console.WriteLine("Finished Test");
        }

        [MethodImpl(MethodImplOptions.NoInlining)]
        static void Main(string[] args)
        {
            Test();
            Test();
            Test(); //crashs here at GC.Collect
        }
    }
}

originally reported here: https://developercommunity.visualstudio.com/content/problem/698374/vs2019-and-fatal-error-has-occurred-and-debugging.html