RFR: 8277507: Add jlink.debug system property while launching jpackage tests to help diagonize recent intermittent failures

[Jaikiran Pai]

Can I please get a review of this change which proposes to add more diagnostics when a failure occurs in the jlink tool during the jpackage tests?

As noted in https://bugs.openjdk.java.net/browse/JDK-8277507, so far 3 failures have been reported in jpackage tests (across different test cases) with the same underlying cause coming from the jlink tool. Since this failure isn't specific to one or two tests and seems to be keep happening across these tests in `test/jdk/tools/jpackage/`, I decided to set this system property from one central location in the `HelloApp` which gets used by these tests. These failures have only been reported on macos (and specifically aarch64), but the commit here doesn't do any OS name checks, to keep this change simple. Furthermore, looking at the `jdk.tools.jlink.internal.JlinkTask` code, enabling this system property will _not_ generate any additional logs unless there's an exception thrown by the `jlink` tool, in which case it prints the exception stacktrace. So enabling this by default won't end up increasing the log output or flooding the logs.

With this change, I have run the 3 tests noted in those issues locally to make sure this doesn't break anything else. I have also verified manually that enabling this system property does indeed get propagated to the `JlinkTask` and checked the logs to see that the command line does pass it:

> 
> [17:51:07.123] TRACE: exec: Execute [macosx-x86_64-server-release/images/jdk/bin/jpackage --input ./test/input --dest ./test/output --name "Name With Space" --type pkg -J-Djlink.debug=true --main-jar hello.jar --main-class Hello --verbose](15); inherit I/O...
> [17:51:07.364] Building PKG package for Name With Space.
> [17:51:19.191] Command [PID: -1]:
>     jlink --output /var/folders/7v/cnkwrnx154926cr3289w4rd80000gp/T/jdk.jpackage13608930262477285540/images/image-3713034571561734902/Name With Space.app/Contents/runtime/Contents/Home --module-path macosx-x86_64-server-release/images/jdk/jmods --add-modules java.rmi,jdk.management.jfr,jdk.jdi,jdk.charsets,jdk.xml.dom,java.xml,java.datatransfer,jdk.jstatd,jdk.httpserver,java.desktop,java.security.sasl,jdk.zipfs,java.base,jdk.crypto.ec,jdk.javadoc,jdk.management.agent,jdk.jshell,jdk.editpad,jdk.jsobject,java.sql.rowset,jdk.sctp,jdk.unsupported,jdk.jlink,java.smartcardio,java.security.jgss,jdk.nio.mapmode,java.compiler,jdk.dynalink,jdk.unsupported.desktop,jdk.accessibility,jdk.security.jgss,jdk.incubator.vector,java.sql,java.xml.crypto,java.logging,java.transaction.xa,jdk.jfr,jdk.crypto.cryptoki,jdk.net,jdk.random,java.naming,jdk.internal.ed,java.prefs,java.net.http,jdk.compiler,jdk.internal.opt,jdk.naming.rmi,jdk.jconsole,jdk.attach,jdk.internal.le,java.management,jdk.jdwp.agent,jdk
 .incubator.foreign,jdk.internal.jvmstat,java.instrument,jdk.management,jdk.security.auth,java.scripting,jdk.jdeps,jdk.jartool,jdk.jpackage,java.management.rmi,jdk.naming.dns,jdk.localedata --strip-native-commands --strip-debug --no-man-pages --no-header-files
> [17:51:19.192] Output:
>     WARNING: Using incubator modules: jdk.incubator.foreign, jdk.incubator.vector
> 
> [17:51:19.192] Returned: 0
> 

These tests get run in `tier2` and I have no way of running the entire `tier2` locally or relying of GitHub actions which only runs `tier1`. If this change looks OK and is approved, then I would like to request for help running the entire tests against this PR before merging it.

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

Commit messages:
 - 8277507: Add jlink.debug system property while launching jpackage tests to help diagonize recent intermittent failures

Changes: https://git.openjdk.java.net/jdk/pull/6491/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=6491&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8277507
  Stats: 4 lines in 1 file changed: 4 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6491.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6491/head:pull/6491

PR: https://git.openjdk.java.net/jdk/pull/6491