RFR: 8313174: Create fewer predictable port clashes in management tests [v2]

[Kevin Walls]

> Specifically noticed on linux-aarch64, detection of port clashes by LocateRegistry.createRegistry(port) appears "racy".
> 
> Predictable port clashes can be avoided, tests that are likely to run at the same time should not choose the same port.
> 
> Why now?  The RMI related parts are obviously fairly stable these days, as are the tests themselves.
> Our OS version/host mix for testing may have changed.  The problems I looked into were on ol8-aarch64.
> 
> It doesn't seem necessary to add complexities to the tests, or change LocateRegistry much at this point, when a simple change to the tests can avoid asking for so many port clashes.
> 
> 
> 
> test/jdk/javax/management/remote/mandatory/passwordAuthenticator/RMIPasswdAuthTest.java:            int port = 5800;  	// 5801 to 5820
> test/jdk/javax/management/remote/mandatory/passwordAuthenticator/RMIAltAuthTest.java:            int port = 5800;	// 5821 to 5840
> test/jdk/javax/management/remote/mandatory/socketFactories/RMISocketFactoriesTest.java:            int port = 5800;	// 5841 to 5860
> test/jdk/javax/management/remote/mandatory/subjectDelegation/SubjectDelegation1Test.java:            int port = 5800;	// 5861 to 5880
> test/jdk/javax/management/remote/mandatory/subjectDelegation/SubjectDelegation2Test.java:            int port = 5800;	// 5881 to 5900
> test/jdk/javax/management/remote/mandatory/subjectDelegation/SubjectDelegation3Test.java:            int port = 5800;	// 5901 to 5920

Kevin Walls has updated the pull request incrementally with one additional commit since the last revision:

  port range fix

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/15039/files
  - new: https://git.openjdk.org/jdk/pull/15039/files/6093573c..29b345b9

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15039&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15039&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/15039.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15039/head:pull/15039

PR: https://git.openjdk.org/jdk/pull/15039