RFR (Preliminary): 8248194: Need better support for running SA tests on core files

[Chris Plummer]

Hello,

Please help with a preliminary review of changes to add better support 
for writing SA tests that work on core files:

https://bugs.openjdk.java.net/browse/JDK-8248194
http://cr.openjdk.java.net/~cjplummer/8248194/webrev.00/index.html

As pointed out, this is a preliminary review. I suspect there will be 
some feedback for changes/improvements. Also, I still need to work out a 
final solution for how to get LingeredApp to produce a crash. What I 
currently have works but is somewhat of a hack w.r.t. the makefile 
change, so you can ignore the makefiile change for now. I'm working on a 
more proper solution with the build team.

As outlined in the CR, these are the 3 main goals of this CR:

1. SATestUtils should include support for finding the core file. This 
includes parsing the output of the crashed process to locate where the 
core file was saved, and returning this location to the user.

2. SATestUtils should include support for adding the "ulimit -c 
unlimited" prefix to the command that will produce the core file, 
allowing the overriding of any lower limit so we can be sure the core 
file will be produced.

3. LingeredApp should include support for producing a core file.

As proof of concept for these 3 changes in test library support, I'm 
updating the following 3 tests:

ClhsdbCDSCore.java: Use the SATestUtils support listed above. This test 
does not use LingeredApp, so those improvements don't apply.

TestJmapCore.java: Use the SATestUtils support listed above. This test 
does not use LingeredApp, so those improvements don't apply.

ClhsdbFindPC.java: Use all the above features, including having 
LingeredApp produce a core file. This is the only test modified to start 
testing on core files that didn't previously do so. It still also tests 
on a live process.

In the future more Clhsdb tests will be converted to work on core files 
in a manner similar to ClhsdbFindPC.

The new SATestUtils code is borrowed from (more like ripped out of) 
ClhsdbCDSCore.java and TestJmapCore.java. They both had a lot of code 
dedicated to finding the core file and also applying "ulimit -c 
unlimitted" if necessary, but didn't do so in quite the same way. Now 
both these tests share code in SATestUtils.java. One thing I did drop is 
TestJmapCore.java use of ":KILLED_PID" in the output to help find the 
core file. It's no longer necessary based on the smarter core locating 
code I pulled from ClhsdbCDSCore.java.

thanks,

Chris