WebMethod returns null if there is no other parameter before the holder parameter

[LanceAndersen]

Previously tracked via: https://bugs.openjdk.java.net/browse/JDK-8170462

To reproduce the issue:

1. wsgen -cp . wstest.EchoImpl against the following java file:
   package wstest;

import javax.jws.WebMethod;
import javax.jws.WebParam;
import javax.jws.WebService;
import javax.xml.ws.Holder;
import java.rmi.RemoteException;
import javax.jws.soap.SOAPBinding;

@webservice
@SOAPBinding(style=SOAPBinding.Style.RPC)
public class EchoImpl {
@webmethod
public String holderOperation(@WebParam(name="holder1", mode=WebParam.Mode.INOUT)Holder holder1,
@WebParam(name="holder2", mode=WebParam.Mode.INOUT)Holder holder2) throws RemoteException{
holder1.value += "1";
holder2.value += "2";
return "success";
}
}

2. start the web service with the following java file:
   package wstest;

import javax.xml.ws.Endpoint;

public class EchoService {
public static void main(String[] args) {
Endpoint.publish("http://localhost:8080/WebServices/echoimpl", new EchoImpl());
}
}

3. generate the client:
   wsimport -keep -p wstest.server http://localhost:8080/WebServices/echoimpl?wsdl

4. run the client test with the following java file:
   import java.rmi.;
   import javax.naming.;
   import wstest.server.*;
   import javax.xml.ws.Holder;

public class EchoClient {
public static void main(String[] args) {
EchoImplService service = new EchoImplService();
EchoImpl port = service.getPort(EchoImpl.class);
Holder h1 = new Holder("1");
Holder h2 = new Holder("2");
String result = port.holderOperation(h1, h2);

    System.out.println(result); 
    System.out.println(h1.value); 
    System.out.println(h2.value); 
} 

}

Will get:
null
11
22

Note:

1. Obviously some changes made the result better, now only the return value is null.
2. If removing @SOAPBinding(style=SOAPBinding.Style.RPC) from EchoImpl java file or inserting a non-holder parameter at the first place in holderOperation method, it will have return value.