RFR: 8347270: Remove unix_getParentPidAndTimings and unix_getCmdlineAndUserInfo [v2]

[Matthias Baesken]

> The functions unix_getParentPidAndTimings and unix_getCmdlineAndUserInfo in src/java.base/unix/native/libjava/ProcessHandleImpl_unix.c used to hold an implementation that was shared between Solaris and AIX. Linux and MacOS already had specific implementations. After the removal of the Solaris port, these two functions can be removed in favor of inline implementations of os_getParentPidAndTimings and os_getCmdlineAndUserInfo in src/java.base/aix/native/libjava/ProcessHandleImpl_aix.c.

Matthias Baesken has updated the pull request incrementally with one additional commit since the last revision:

  remove unix_getChildren, adjust COPYRIGHT info

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Changes:
  - all: https://git.openjdk.org/jdk/pull/23013/files
  - new: https://git.openjdk.org/jdk/pull/23013/files/d49d3d36..d4b539e6

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=23013&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23013&range=00-01

  Stats: 267 lines in 4 files changed: 123 ins; 137 del; 7 mod
  Patch: https://git.openjdk.org/jdk/pull/23013.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23013/head:pull/23013

PR: https://git.openjdk.org/jdk/pull/23013