Add DB2TestDialect

Author: bahusoid

src/NHibernate.Test/TestDialects/DB2TestDialect.cs

@@ -0,0 +1,11 @@
+namespace NHibernate.Test.TestDialects
+{
+	public class DB2TestDialect: TestDialect
+	{
+		public DB2TestDialect(Dialect.Dialect dialect) : base(dialect)
+		{
+		}
+
+		public override bool SupportsComplexExpressionInGroupBy => false;
+	}
+}