WinForms Designer should not modify class fields of generic types outside designer file

Here is the sample code:

    using System;
    using System.Collections.Generic;
    using System.Windows.Forms;

    namespace WinForm1
    {
        public partial class Form1 : Form
        {
            string simple = "abc";
            List<string> myList = new List<string>();

            public Form1()
            {
                InitializeComponent();
            }
        }
    }

Should not become

    using System;
    using System.Collections.Generic;
    using System.Windows.Forms;

    namespace WinForm1
    {
        public partial class Form1 : Form
        {
            string simple = "abc";
            System.Collections.Generic.List<string> myList;

            public Form1()
            {
                InitializeComponent();
            }
        }
    }