Do not get access to "this" in breakpoint conditions for expression properties/methods

Version Used: Version 15.6.0 Preview 1.1 [27217.0.d15.6]

Steps to Reproduce:

    class Program
    {
        private readonly string _foo;

        public string Foo => _foo; // Location 1

        public string FooBar() => _foo; // Location 2
    }

1. Set a breakpoint on Location 1 and Location 2
2. Right-click breakpoint and choose Conditions
3. Check conditions and in expression text box, type this.

Expected Behavior: For completion window to open and get intellisense for members of the class (ie _foo)

Actual Behavior: Actual, completion window doesn't open. If you force it open CTRL+Space there's no access to "this" members