RFR: 8256178: Add RAII object for file lock

[Yasumasa Suenaga]

This PR is subtask of [JDK-8256008](https://bugs.openjdk.java.net/browse/JDK-8256008) (#1106)

`LogFileStreamOutput::write()` uses `os::flockfile()` and `os::funlockfile()` to serialize write ops. It is better to use RAII because we can ensure `os::funlockfile()` call.

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Commit messages:
 - Add RAII object for file lock

Changes: https://git.openjdk.java.net/jdk/pull/1156/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1156&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8256178
  Stats: 17 lines in 1 file changed: 14 ins; 0 del; 3 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1156.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1156/head:pull/1156

PR: https://git.openjdk.java.net/jdk/pull/1156