Immediate/watch window not formatting DateTimes inside loops

Version Used: Visual Studio 2019 Preview 2

🔗 Originally filed as https://devdiv.visualstudio.com/DevDiv/_workitems/edit/215428

Steps to Reproduce:

using System;
using System.Linq;

namespace ConsoleApp1
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var dt = new DateTime(2016, 3, 2);
            var result = Enumerable.Range(1, 1).Select(x => dt.ToString("yyyy")).First();
            Console.WriteLine(result);
        }
    }
}

1. Set a breakpoint on the line with Console.WriteLine

2. When the breakpoint is hit, observe the value of result

3. In the Immediate window, run the following:

   Enumerable.Range(1, 1).Select(x => dt.ToString("yyyy")).First()
   

Expected Behavior:

Step (2) and (3) produce "2016".

Actual Behavior:

Step (2) produces "2016".

Step (3) produces "3/2/2016 12:00:00 AM".