If you build Hotspot with certain features disabled, e.g. jfr or jvmti, then the code present in some modules, in these cases jdk.jfr or jdk.jdwp.agent, will not work and just be pointless.

Intuitively, there should be some kind of connection in the build system, so you exclude these "feature dependent" modules, if the JVM lacks the corresponding features.

There is a lot to figure out about this seemingly simple intuition. For instance, how do we handle the case where multiple JVMs are built, with different feature sets? In what direction should the configuration go -- should we exclude jdk.jfr if we disable the jfr feature in Hotspot, or should we disable the jfr feature if we exclude jdk.jfr? Or both?

This PR was created to track the discussion arising in https://github.com/openjdk/jdk/pull/23805.