sort BeanDefinitionRegistryPostProcessors added by other BeanDefinitionRegistryPostProcessors

we are having an ordering problem where one BeanDefinitionRegistryPostProcessor adds multiple other BeanDefinitionRegistryPostProcessor s.
those additional ones get applied in arbitrary order (i.e. not in the order that would correspond to their Ordered precedence).

i dropped a commit comment here: https://github.com/spring-projects/spring-framework/commit/bb971cecf15e8c7983cbaf7767851236d132889c#diff-94c72f4a124185c98f882bc9a7038e74R112

ref. also https://jira.spring.io/browse/SPR-10630

problem initially found here: https://github.com/grails/grails-core/issues/10824#issuecomment-334106247

thanks, zyro