[jdk21u-dev] RFR: 8339475: Clean up return code handling for pthread calls in library coding

[Matthias Baesken]

Backport of 8339475 + follow up 8341135

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Commit messages:
 - Backport 2a2ecc994e02049d6d84f083b8e92a51368577bf

Changes: https://git.openjdk.org/jdk21u-dev/pull/1247/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=1247&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8339475
  Stats: 24 lines in 4 files changed: 9 ins; 8 del; 7 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/1247.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/1247/head:pull/1247

PR: https://git.openjdk.org/jdk21u-dev/pull/1247