RFR: 8263635: Add --servername option to jhsdb debugd [v3]

[Yasumasa Suenaga]

> `jhsdb debugd` supports server name prefix with `sun.jvm.hotspot.rmi.serverNamePrefix` system property. It will be used as remote name for SA RMI object. It is "SARemoteDebugger" by default.
> 
> As a result, remote name will be constructed as following:
> 
> 
> //host[:port]/<serverNamePrefix>['_'<id>]
> 
> 
> However we have no way to set it excepting system property. jhsdb should provide the way to set it as a command line option.
> 
> serverNamePrefix is used for RMI object name, so "server name" is more suitable for it. Thus I will add `--servername` to `jhsdb debugd` for this purpose.
> And also we should add the way to specify it when we connect to debug server. I will add it like `--connect id at server:1234/servername`.
> 
> I've also filed [CSR for this PR](https://bugs.openjdk.java.net/browse/JDK-8265897). Please review it.
> This PR modifies DisableRegistryTest.java, but it has been addressed in ProblemList-zgc.txt now. So this PR does not affect ZGC.

Yasumasa Suenaga has updated the pull request incrementally with one additional commit since the last revision:

  8263635: Add --servername option to jhsdb debugd

-------------

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/3669/files
  - new: https://git.openjdk.java.net/jdk/pull/3669/files/af154a77..03ed5d19

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=3669&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=3669&range=01-02

  Stats: 131 lines in 12 files changed: 26 ins; 12 del; 93 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3669.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3669/head:pull/3669

PR: https://git.openjdk.java.net/jdk/pull/3669