RFR: JDK-8324753: [AIX] adjust os_posix after JDK-8318696

[David Holmes]

On Fri, 26 Jan 2024 13:29:15 GMT, Matthias Baesken <mbaesken at openjdk.org> wrote:

> [JDK-8318696](https://bugs.openjdk.org/browse/JDK-8318696) changed not only Linux related os coding, but also os_posix.
> Unfortunately, this touches AIX as well, we use there now the non-large-file functions (e.g. lseek) which could be problematic.
> See also https://www.ibm.com/docs/en/aix/7.1?topic=volumes-writing-programs-that-access-large-files .

Also apologies for forgetting about AIX in the original change.

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

Marked as reviewed by dholmes (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/17587#pullrequestreview-1847673986