Add missing pragma warning for FieldInterceptorProxyBuilder

Author: maca88

src/NHibernate/Proxy/FieldInterceptorProxyBuilder.cs

@@ -16,9 +16,13 @@ internal static class FieldInterceptorProxyBuilder
 		private static readonly PropertyInfo AccessorTypeFieldInterceptorProperty =
 			FieldInterceptorAccessorType.GetProperty(nameof(IFieldInterceptorAccessor.FieldInterceptor));
 		private static readonly System.Type FieldInterceptorType = typeof(IFieldInterceptor);
+		// 6.0 TODO: Remove
 		private static readonly System.Type FieldInterceptorExtensionsType = typeof(FieldInterceptorExtensions);
+#pragma warning disable 618
 		private static readonly MethodInfo FieldInterceptorInterceptMethod = FieldInterceptorType.GetMethod(nameof(IFieldInterceptor.Intercept));
+#pragma warning restore 618
 		private static readonly MethodInfo FieldInterceptorMarkDirtyMethod = FieldInterceptorType.GetMethod(nameof(IFieldInterceptor.MarkDirty));
+		// 6.0 TODO: Remove and replace usages with FieldInterceptorInterceptMethod
 		private static readonly MethodInfo FieldInterceptorInterceptExtensionMethod = FieldInterceptorExtensionsType.GetMethod(nameof(FieldInterceptorExtensions.Intercept));
 		private static readonly System.Type AbstractFieldInterceptorType = typeof(AbstractFieldInterceptor);
 		private static readonly FieldInfo AbstractFieldInterceptorInvokeImplementationField =