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

[Joshua Cao]

> 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

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/13344/files
  - new: https://git.openjdk.org/jdk/pull/13344/files/76f8434c..bed0c81c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13344&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13344&range=02-03

  Stats: 3 lines in 1 file changed: 0 ins; 2 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/13344.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13344/head:pull/13344

PR: https://git.openjdk.org/jdk/pull/13344