EnC: Changing signature of an async method or an iterator does not work

[tmat]

A state machine can be in-progress and emitting new kick-off method does not affect the old MoveNext method. The old method keeps executing but the execution no longer matches the code.

The same issue is with rename, which is only blocked when there is an active statement in the method body but not when the state machine is otherwise in-progress.

using System;
using System.Threading.Tasks;

class Program
{
    static async Task Main()
    {
        await F(1);
    }

    static async Task F(byte a)
    {
        Console.WriteLine($"1: {a}");
        await Task.Delay(1);
        Console.WriteLine($"2: {a}");
        await Task.Delay(1);
    }
}

After changing the parameter type to int, inserting some whitespace and stepping:

See tests.