RFR: 8286540: Build failure caused by missing DefaultPollProvider implementation on AIX

[Tyler Steele]

This change provides a stub implementation of DefaultPollerProvider on AIX. This is a temporary measure to ensure AIX can still be built while work on a full implementation is under way.

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Commit messages:
 - Fix copyright base year
 - Adds stub impl for DefaultPollerProvider on AIX

Changes: https://git.openjdk.java.net/jdk/pull/8658/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8658&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8286540
  Stats: 107 lines in 2 files changed: 107 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8658.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8658/head:pull/8658

PR: https://git.openjdk.java.net/jdk/pull/8658