RFR: 8357179: Deprecate VFORK launch mechanism from Process implementation (linux)

[Thomas Stuefe]

For the ratio behind this please see the companion CSR: https://bugs.openjdk.org/browse/JDK-8357180.

We plan to deprecate this in JDK 25 and to remove it in JDK 26.

This patch just writes a deprecation message to stderr:


08:46:38 thomas at starfish java -Djdk.lang.Process.launchMechanism=VFORK SimpleSpawn ls
VFORK MODE DEPRECATED
The VFORK launch mechanism has been deprecated for being dangerous.
It will be removed in a future java version. Either remove the
jdk.lang.Process.launchMechanism property (preferred) or use FORK mode
instead (-Djdk.lang.Process.launchMechanism=FORK).
...

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Commit messages:
 - deprecate-vfork

Changes: https://git.openjdk.org/jdk/pull/25282/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25282&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8357179
  Stats: 14 lines in 1 file changed: 10 ins; 2 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/25282.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25282/head:pull/25282

PR: https://git.openjdk.org/jdk/pull/25282