ParserError with DataRowVersion #517

Hi there.

I've got a parser error when parsing this code:

` [TestMethod]
public void WhenParsingThisCodeReturnNoError()
{
const string sampleCode = @"
using System.Data;
namespace Test
{
public class TestClass
{
void TestMethod()
{
DataRow row = null;

  row[""AnyField""] = row.RowState == DataRowState.Deleted ? 
    row[""OtherField"", DataRowVersion.Original] : 
    row[""SomeField""];
}

}
}";
var parser = new ICSharpCode.NRefactory.CSharp.CSharpParser();
var syntaxTree = parser.Parse(sampleCode);
Assert.IsTrue(syntaxTree.Errors.Count == 0, "Parser error");
}`

If I remove the DataRowVersion, the parse is OK:

row[""AnyField""] = row.RowState == DataRowState.Deleted ?
row[""OtherField""] :
row[""SomeField""];

Thanks,
Wilsade