RFR: 8375006: [Linux] Remove obsolete O_CLOEXEC check in os::open

[David Holmes]

On Mon, 12 Jan 2026 12:50:48 GMT, Jonas Norlinder <jnorlinder at openjdk.org> wrote:

> Linux got support for O_CLOEXEC in 2.6.23. This version was released in October 9, 2007. OpenJDK does not support versions that old anymore so this logic can be removed.

This cleanup seems fine.

Thanks

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Marked as reviewed by dholmes (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/29168#pullrequestreview-3652621793