taross-f/aggregate_check.cs

## aggregate_check.cs
void Main()
{
    new int[0].DefaultIfEmpty().Aggregate((x, y) => x + y).Dump();
    new int[0].DefaultIfEmpty().Dump();
    new int[0].Aggregate((x, y) => x + y).Dump(); // dead
}
	void Main()
	{
	new int[0].DefaultIfEmpty().Aggregate((x, y) => x + y).Dump();
	new int[0].DefaultIfEmpty().Dump();
	new int[0].Aggregate((x, y) => x + y).Dump(); // dead
	}