I have updated to Azul Zulu 8u282 JRE and I noticed a new JAR file that wasn't there in the previous version I used (8u265). It's called 'crs-agent.jar' and the class files are all inside the package structure 'com.azul.crs.*'. When I decompile them with IntelliJ it looks like some diagnostic or reporting stuff and there's also networking at work.
I went through lot's of release notes of current and old releases on the Azul website but there is no information about this CRS. Wikipedia yields several results for that acronym with 'Carrier Routing System' making the most sense.
So what is this JAR for? Can I just delete it?
Yes, you can ignore/delete this file. It's not used and was added for experimental features that are turned off and are never used at the moment.
The latest release notes refer to this as:
New Experimental Features
Zulu includes optional experimental support for interaction with connected runtime services through an emerging protocol. These experimental capabilities are enabled by the -XX:+UseCRS flag and are turned off by default. The -XX:+UnlockExperimentalVMOptions must also be on for this option to work.