RFR: 8280881: (fs) UnixNativeDispatcher.close0 may throw UnixException [v7]

[Brian Burkhalter]

> Re-specify `sun.nio.fs.UnixNativeDispatcher.close0()` to throw `sun.nio.fs.UnixException` and modify callers either to ignore it or to rethrow it as an `IOException`, as appropriate.

Brian Burkhalter has updated the pull request incrementally with one additional commit since the last revision:

  8280881: straggling s/null/e -> null/ in one place

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/7467/files
  - new: https://git.openjdk.java.net/jdk/pull/7467/files/595bd975..0bc1ffd0

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=7467&range=06
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=7467&range=05-06

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7467.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7467/head:pull/7467

PR: https://git.openjdk.java.net/jdk/pull/7467