[jdk21u-dev] RFR: 8325567: jspawnhelper without args fails with segfault

[Elif Aslan]

Clean backport. Testing is in progress

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Commit messages:
 - Backport 262747094670b00ac63463a059074afa9b81d8a4

Changes: https://git.openjdk.org/jdk21u-dev/pull/414/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=414&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8325567
  Stats: 62 lines in 2 files changed: 62 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/414.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/414/head:pull/414

PR: https://git.openjdk.org/jdk21u-dev/pull/414