RFR: JDK-8164913: JVMTI.agent_load dcmd should show useful error message

[Yasumasa Suenaga]

Hi all,

If we try to attach invalid JVMTI agent via JVMTI.agent_load dcmd, we will get
"Command executed successfully". However, it implies error in JVMTIAgentLoadDCmd.

This message is from JCmd.java when jcmd does not receive output from target VM.
So we should send error message from JVMTIAgentLoadDCmd.

I uploaded a webrev for it. Could you review it?

   http://cr.openjdk.java.net/~ysuenaga/JDK-8164913/webrev.00/

I cannot access JPRT.
So I need a sponsor.


Thanks,

Yasumasa