Do not use runtime method generator

Author: hazzik

src/NHibernate/Linq/Functions/HasFlagGenerator.cs

@@ -1,33 +1,30 @@
-using System;
+using System;
 using System.Collections.ObjectModel;
 using System.Linq.Expressions;
 using System.Reflection;
 using NHibernate.Hql.Ast;
 using NHibernate.Linq.Visitors;
+using NHibernate.Util;
 
 namespace NHibernate.Linq.Functions
 {
-	internal class HasFlagGenerator : BaseHqlGeneratorForMethod, IRuntimeMethodHqlGenerator
+	internal class HasFlagGenerator : BaseHqlGeneratorForMethod
 	{
-		private const string _bitAndFunctionName = "band";
-
-		public bool SupportsMethod(MethodInfo method)
-		{
-			return method.Name == nameof(Enum.HasFlag) && method.DeclaringType == typeof(Enum);
-		}
-
-		public IHqlGeneratorForMethod GetMethodGenerator(MethodInfo method)
+		internal HasFlagGenerator()
 		{
-			return this;
+			SupportsMethod = new []
+			{
+				ReflectHelper.FastGetMethod(Enum.HasFlag, default(Enum))
+			};
 		}
 
 		public override HqlTreeNode BuildHql(MethodInfo method, Expression targetObject, ReadOnlyCollection<Expression> arguments, HqlTreeBuilder treeBuilder, IHqlExpressionVisitor visitor)
 		{
 			return treeBuilder.Equality(
 						treeBuilder.MethodCall(
-							_bitAndFunctionName,
-							 visitor.Visit(targetObject).AsExpression(),
-							 visitor.Visit(arguments[0]).AsExpression()),
+							"band",
+							visitor.Visit(targetObject).AsExpression(),
+							visitor.Visit(arguments[0]).AsExpression()),
 						visitor.Visit(arguments[0]).AsExpression());
 		}
 	}