RFR: 8312125: Refactor CDS enum class handling [v3]

[Ioi Lam]

> Please review this simple refactoring of the CDS code for handling enum classes. The code is moved to new files cdsEnumKlass.cpp/hpp. There's otherwise no change.

Ioi Lam 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 four additional commits since the last revision:

 - Merge branch 'master' into 8312125-refactor-cds-enum-class-handling
 - @calvinccheung comments
 - fixed copyright
 - 8312125: Refactor CDS enum class handling

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Changes:
  - all: https://git.openjdk.org/jdk/pull/20013/files
  - new: https://git.openjdk.org/jdk/pull/20013/files/49dc109e..fcd987fb

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20013&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20013&range=01-02

  Stats: 5501 lines in 320 files changed: 2525 ins; 1662 del; 1314 mod
  Patch: https://git.openjdk.org/jdk/pull/20013.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20013/head:pull/20013

PR: https://git.openjdk.org/jdk/pull/20013