RFR: JDK-8300783: Consolidate byteswap implementations [v12]

[Justin King]

> Deduplicate byte swapping implementations by consolidating them into `utilities/byteswap.hpp`, following `std::byteswap` introduced in C++23. Further simplification of `Bytes` will follow in https://github.com/openjdk/jdk/pull/12078.

Justin King has updated the pull request incrementally with four additional commits since the last revision:

 - Update copyright
   
   Signed-off-by: Justin King <jcking at google.com>
 - Add missing include
   
   Signed-off-by: Justin King <jcking at google.com>
 - Remove unused include
   
   Signed-off-by: Justin King <jcking at google.com>
 - Reorganize tests
   
   Signed-off-by: Justin King <jcking at google.com>

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/12114/files
  - new: https://git.openjdk.org/jdk/pull/12114/files/d43b9f10..139c4205

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=12114&range=11
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12114&range=10-11

  Stats: 254 lines in 3 files changed: 152 ins; 102 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/12114.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12114/head:pull/12114

PR: https://git.openjdk.org/jdk/pull/12114