NH-3800 - Ensure only NewArrayInit expressions are flattened

Author: PleasantD

src/NHibernate/Linq/ReWriters/ArrayIndexExpressionFlattener.cs

@@ -24,7 +24,7 @@ protected override Expression VisitBinaryExpression(BinaryExpression expression)
 				return visitedExpression;
 
 			var expressionList = expression.Left as NewArrayExpression;
-			if (expressionList == null)
+			if (expressionList == null ||  expressionList.NodeType != ExpressionType.NewArrayInit)
 				return visitedExpression;
 
 			return VisitExpression(expressionList.Expressions[(int)index.Value]);