[11] RFR(S) : 8205687 : TimeoutHandler generates huge core files

[Igor Ignatyev]

http://cr.openjdk.java.net/~iignatyev//8205687/webrev.00/index.html
> 18 lines changed: 3 ins; 5 del; 10 mod; 

Hi all,

could you please review this small fix for TimeoutHandler? gcore dumps non committed memory, which is a problem when JVM is run w/ ZGC or in other configurations where memory is reserved but not committed. the fix replaces invocation of gcore w/ 'kill -ABRT'. as kill has to be the last command run by TimeoutHandler, I've changed jdk.test.failurehandler.ToolKit to run action after we get a list of the process's children and also changed GathererFactory to run "common" part before os-specific part.

NB 'kill' will generate core file only if a host has appropriate core file limit and core file handling settings, therefore you might observe that core files aren't generated if your hosts aren't set up correspondingly. 

JBS: https://bugs.openjdk.java.net/browse/JDK-8205687
webrev: http://cr.openjdk.java.net/~iignatyev//8205687/webrev.00/index.html

Thanks,
-- Igor