RFR: JDK-8315458 Implementation of Implicitly Declared Classes and Instance Main Method (Second Preview) [v12]

[Jim Laskey]

> Address changes from JEP 445 to JEP 463.
> 
> - Move from a SYNTHETIC unnamed class to a MANDATED implicit class.
> 
> - Don't mark class on read.
> 
> - Remove reflection and annotation processing related to unnamed classes.
> 
> - Simplify main method search.

Jim Laskey 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 12 additional commits since the last revision:

 - Merge remote-tracking branch 'upstream/master' into 8315458
 - Don't get args unless necessary
 - Remove unnamed classes from examples.not-yet.txt
 - Requested corrections
 - Changes recommended by Jan
 - Revised implicit class test
 - Don't store main method info globally. Use addition calls to fetch info.
 - Update JEP number in PreviewFeature
 - Remove MANDATED flag from implicit classes
 - Remove .orig files
 - ... and 2 more: https://git.openjdk.org/jdk/compare/f04a1529...0bd5b477

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/16461/files
  - new: https://git.openjdk.org/jdk/pull/16461/files/4b3c03fe..0bd5b477

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=16461&range=11
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16461&range=10-11

  Stats: 23833 lines in 485 files changed: 11893 ins; 4870 del; 7070 mod
  Patch: https://git.openjdk.org/jdk/pull/16461.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16461/head:pull/16461

PR: https://git.openjdk.org/jdk/pull/16461