Provide better exception for bad INotifyCollectionChanged index bounds (#948)

Xamarin.Forms.Platform.iOS/Renderers/ListViewRenderer.cs

@@ -500,6 +500,11 @@ namespace Xamarin.Forms.Platform.iOS
 
 			var groupReset = resetWhenGrouped && Element.IsGroupingEnabled;
 
+			var lastIndex = Control.NumberOfRowsInSection(section);
+			if (e.NewStartingIndex > lastIndex || e.OldStartingIndex > lastIndex)
+				throw new ArgumentException(
+					$"Index '{Math.Max(e.NewStartingIndex, e.OldStartingIndex)}' is greater than the number of rows '{lastIndex}'.");
+
 			switch (e.Action)
 			{
 				case NotifyCollectionChangedAction.Add: