Simplification of Count(*) with multiple group by can generate wrong result

```C#
ss.Set().GroupBy(e => e.CustomerID)
.Select(g => new
{
g.Key,
A = ss.Set().Where(e => e.City == "Seattle").GroupBy(e => e.City)
.Select(g2 => g2.Count() + g.Min(e => e.OrderID))
.OrderBy(e => 1)
.FirstOrDefault()
})
```
Generates
```SQL
SELECT [o].[CustomerID] AS [Key], COALESCE((
SELECT TOP(1) COUNT(*) + MIN([o].[OrderID])
FROM [Employees] AS [e]
WHERE [e].[City] = N'Seattle'
GROUP BY [e].[City]
ORDER BY (SELECT 1)), 0) AS [A]
FROM [Orders] AS [o]
GROUP BY [o].[CustomerID]
```
Which works correctly.
But if the `g.Min(e => e.OrderID)` is converted to `g.Count()` then generate the SQL like this
```SQL
SELECT [o].[CustomerID] AS [Key], COALESCE((
SELECT TOP(1) COUNT(*) + COUNT(*)
FROM [Employees] AS [e]
WHERE [e].[City] = N'Seattle'
GROUP BY [e].[City]
ORDER BY (SELECT 1)), 0) AS [A]
FROM [Orders] AS [o]
GROUP BY [o].[CustomerID]
```
Now all of sudden the aggregate which is supposed to count records on outer grouping is computing that on inner one producing wrong results.