How do I map a tomcat version to source code

[Hoa Phan]

On
https://github.com/apache/tomcat <https://github.com/apache/tomcat>
When I checked the “tag” of 8.x I only see:

8_0_RC_***

Is there a quick way to know exactly which revision to check out to debug 
apache-tomcat-8.0.36 that I am running?
Why isn’t there tag that have that exact version?

Thanks.

Regards,

Hoa Phan.