RFR: JDK-8310061: Note if implicit annotation processing is being used [v5]

[Joe Darcy]

> Emit a note warning of the possibility of changing the implicit running of annotation processors in a future release.

Joe Darcy has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 11 additional commits since the last revision:

 - Merge branch 'master' into JDK-8310061
 - Expand cases where an annotation processor path is detected.
 - Appease jcheck.
 - Update test.
 - Respond to review feedback.
 - Merge branch 'master' into JDK-8310061
 - Add a maintenance breadcrumb.
 - Copyright update.
 - Update tests and implementation.
 - Merge branch 'master' into JDK-8310061
 - ... and 1 more: https://git.openjdk.org/jdk/compare/0132b89b...6cbeec6c

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/14499/files
  - new: https://git.openjdk.org/jdk/pull/14499/files/f3981ee7..6cbeec6c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=14499&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=14499&range=03-04

  Stats: 12731 lines in 626 files changed: 5313 ins; 3694 del; 3724 mod
  Patch: https://git.openjdk.org/jdk/pull/14499.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14499/head:pull/14499

PR: https://git.openjdk.org/jdk/pull/14499