RFR: 8360025: (se) Convert kqueue Selector Implementation to use FFM APIs [v2]

[Darragh Clarke]

> This PR aims to Panamize the Java Kqueue implementation, This is based on the work that was previously shared in https://github.com/openjdk/jdk/pull/22307 , The main change since then is that this branch takes advantage of the changes made in https://github.com/openjdk/jdk/pull/25043 to allow for better performance during errno handling.
> 
> These changes feature a lot of Jextract generated files, though alterations have been made in relation to Errno handling and performance improvements.
> 
> I will update this description soon to include performance metrics on a few microbenchmarks, though currently it's roughly 2% to 3% slower with the changes, which is somewhat expected, though there are still a few ideas of possible performance improvements that could be tried. Any suggestions or comments in that area are more than welcome however.

Darragh Clarke has updated the pull request incrementally with one additional commit since the last revision:

  implementing feedback, adding missing errno checks, cleanup

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Changes:
  - all: https://git.openjdk.org/jdk/pull/25546/files
  - new: https://git.openjdk.org/jdk/pull/25546/files/4878d558..e2207883

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=25546&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=25546&range=00-01

  Stats: 322 lines in 8 files changed: 168 ins; 135 del; 19 mod
  Patch: https://git.openjdk.org/jdk/pull/25546.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25546/head:pull/25546

PR: https://git.openjdk.org/jdk/pull/25546