RFR: 8300829: Make CtwRunner available as an independent tool [v4]

[Paul Hohensee]

On Thu, 6 Apr 2023 17:55:24 GMT, Joshua Cao <duke at openjdk.org> wrote:

>> 1. ~~Create an independent jar file with CtwRunner as the main class to make it easier to run~~. Not needed anymore thanks to @navyxliu 's comments. We can use the original `ctw.jar` because it already has ctwrunner class.
>> 2. Output the class files directly into the destination directory. Currently, CTW expects a `wb.jar`, but the jtreg tests that use CTWRunner has class files outside of a jar.
>> 3. Introduce `sun.hotspot.tools.ctwrunner.ctw_extra_args` option to pass extra arguments to CTW. Arguments are comma separated because working with spaces in bash can be kind of awkward, but I'm open to changing this part.
>> 
>> ### Motivation
>> CTWRunner is a wrapper around CTW that will continue compiling beyond failure. It can be useful for testing compilation with certain flags. For example, one could run
>> 
>> 
>> JAVA_OPTIONS="-Dsun.hotspot.tools.ctwrunner.ctw_extra_args=-XX:+StressLCM,-XX:+StressGCM" ./ctwrunner.sh modules:java.base
>> 
>> 
>> To test compiling the java.base module with `-XX:+StressLCM -XX:+StressGCM`. This is advantageous over uses CTW because we can see the full list of crashes for the entire module.
>
> Joshua Cao has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Don't create unnecessary output dir

Lgtm.

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Marked as reviewed by phh (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/13344#pullrequestreview-1375352014