RFR: 8298420: PEM API: Implementation (Preview) [v3]

[Anthony Scarpino]

> Hi all,
> 
> I need a code review of the PEM API.  Privacy-Enhanced Mail (PEM) is a format for encoding and decoding cryptographic keys and certificates.  It will be integrated into JDK24 as a Preview Feature.  Preview features does not permanently define the API and it is subject to change in future releases until it is finalized.
> 
> Details about this change can be seen at [PEM API JEP](https://bugs.openjdk.org/browse/JDK-8300911).
> 
> Thanks
> 
> Tony

Anthony Scarpino has updated the pull request incrementally with one additional commit since the last revision:

  review comments and optimizations

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/17543/files
  - new: https://git.openjdk.org/jdk/pull/17543/files/719ba350..49b72912

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17543&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17543&range=01-02

  Stats: 309 lines in 17 files changed: 79 ins; 55 del; 175 mod
  Patch: https://git.openjdk.org/jdk/pull/17543.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17543/head:pull/17543

PR: https://git.openjdk.org/jdk/pull/17543