RFR: JDK-8289147: unify os::infinite_sleep on posix platforms

[Matthias Baesken]

os::infinite_sleep could be unified on the POSIX platforms (linux, bsd, aix).

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

Commit messages:
 - JDK-8289147

Changes: https://git.openjdk.org/jdk/pull/9279/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9279&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8289147
  Stats: 27 lines in 4 files changed: 6 ins; 21 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/9279.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9279/head:pull/9279

PR: https://git.openjdk.org/jdk/pull/9279