Restored original singleton-only adaptInnerBeanName behavior, avoiding endless unique name calculation for every single prototype instance. Non-named inner BeanDefinition objects now suffixed with an identity hex code analogous to non-named XML bean definitions, largely avoiding naming collisions to begin with. After SPR-11246, post-processors can deal with unstable classes per bean name, so occasional collisions aren't a hard problem anymore.
Issue: SPR-11545
(cherry picked from commit 5308b3e)