Can't start JMX/tool agents into application running on the JRE or start with `java -m <module>`

 `java -m <module>` does not resolve the jdk.management.agent or java.instrument modules unless they are transitively required by the initial module (or `--add-modules` is used to add them as roots). This means that tools cannot start the JMX agent or load a tool agent into the running VM.

Additionally, the refactoring in JDK-8173608 means that the jdk.management.agent is not resolved by default for applications deployed with the JRE.

There are several approaches to addressing these issue. This JIRA issue is a placeholder for now until a preferred approach emerges.