RFR: 8330989: unify os::create_binary_file across Posix platforms

[Matthias Baesken]

Seems os::create_binary_file can be unified across Posix platforms.

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Commit messages:
 - JDK-8330989

Changes: https://git.openjdk.org/jdk/pull/18918/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18918&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8330989
  Stats: 30 lines in 4 files changed: 7 ins; 23 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/18918.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18918/head:pull/18918

PR: https://git.openjdk.org/jdk/pull/18918