How does rt_finalized function work exactly? (Fixing bugs regarding Destroy).

[12345swordy]

I can't find any documentation nor can I find any information 
regarding it's implementation. I am asking this, as I focusing on 
fixing bugs that destroy currently has, most noticeably bugs 
regarding attributes. I am not sure that this requires a DIP in 
order to fix this.

https://issues.dlang.org/show_bug.cgi?id=17297
https://issues.dlang.org/show_bug.cgi?id=15246