RFR: 8375297: ZGC: Remove obsolete O_CLOEXEC definition

[duke]

On Wed, 14 Jan 2026 12:14:06 GMT, Jonas Norlinder <jnorlinder at openjdk.org> wrote:

> With [JDK-8375006](https://bugs.openjdk.org/browse/JDK-8375006) integrated we are no longer supporting building with on a system with kernel headers < 2.6.23 and glibc < 2.7.

@JonasNorlinder 
Your change (at version cab7cc476fe558c086ae5e16b0ed9616b52fc801) is now ready to be sponsored by a Committer.

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PR Comment: https://git.openjdk.org/jdk/pull/29230#issuecomment-3750003824