jmx-dev Need reviewer for 6888179: Separate out dependency on CORBA

[Alan Bateman]

As you know, we need to do some re-organization of code in preparation 
for the jdk build generating modules. One dependency that I would like 
to separate out is the dependency on RMI-IIOP and CORBA in the JSR-160 
implementation. The motivation is a possible "management" module that 
wouldn't require "corba" to be installed. The webrev with the proposed 
changes is here:
  http://cr.openjdk.java.net/~alanb/6888179/webrev.00/

In summary, the RMI connectors are changed to use a helper class for 
RMI-IIOP and CORBA. The methods defined by the helper class have all 
CORBA types erased and they simply delegate to a proxy which has an 
implementation in the com.sun.jmx.remote.protocol.iiop package that is 
either present or not present. When not present then methods requiring 
the transport fail gracefully indicating that the iiop protocol is not 
supported.

I ran into two issues that I should point:

1. The bytecode for ProxyStub._releaseReply in RMIConnector didn't match 
the source in the comments. The actual code has a null check that was 
missing from the source. I've updated this for any future maintainers.

2. RMIConnector.findRMIServerJRMP used PortableRemoteObject.narrow to 
check the stub type, which I'm sure was an oversight.

I've run all the tests in test/javax/management/remote (good test 
coverage btw) and don't see any regressions.

Éamonn, Daniel - would you have cycles to review?

-Alan.