Incorrect quick info for ValueTuple<T>

[sharwell]

Version Used: VS 2017 (15.0.0+26228.9)

Steps to Reproduce:

1. Use the following code:

   void Foo()
   {
       var y = ValueTuple.Create(1);
   }

2. Hover over var

3. Hover over y

Expected Behavior:

• In step 2, the result should be struct System.ValueTuple<T>, with T is int.
• In step 3, the result should be ValueTuple<int, int> y

Actual Behavior:

• In step 2, the result is (System.Int32)
• In step 3, the result is (int) y

Neither of these are valid tuple syntaxes in C#.