Roslyn: IDE0024 (Use expression body for properties): Removing extra whitespace

[NickCraver]

Version Used: VS 2017 RC 15.0.26020.0

Steps to Reproduce:

1. Start with this a sample program:
   ```c#
   class Program
   {
   static void Main(string[] args) { }

   private string _prop = "HELLO THERE!";
   public string Prop { get { return _prop; } }

   public string OtherThing => "Pickles";
   }

2. `Ctrl+.` on `public string Prop { get { return _prop; } }`
3. Select "Use expression body for properties"
4. Observe the line below the `Prop` property being removed, result:
```c#
    public string Prop => _prop;
    public string OtherThing => "Pickles";

Screenshot:

Expected Behavior: Suggestion should not remove the unrelated line below the property.

Actual Behavior: Line below the property is removed.

[NickCraver]

A more severe instance of this is when there was no extra line to remove, causing multiple properties to appear on a single line. Here's an example:

Before:
```c#
public NameValueCollection Form
{
get { return formVariables; }
}
private NameValueCollection formVariables = new NameValueCollection();

After:
```c#
public NameValueCollection Form => formVariables; private NameValueCollection formVariables = new NameValueCollection();

[CyrusNajmabadi]

Fixed with https://github.com/dotnet/roslyn/pull/16987