Fix for NH-3119: The ReflectionOptimizer is never used when a component is instantiated.

This is a fix for [NH-3119](https://nhibernate.jira.com/browse/NH-3119) that is different from the attached patch there. My solution is like the one Fabio implemented for [NH-1587](https://nhibernate.jira.com/browse/NH-1587) (see his changes [here](https://github.com/nhibernate/nhibernate-core/commit/d15064fc07729f489f89972288e69a7ce4903232)).