RFR: 8353741: Eliminate table lookup in UUID.toString [v7]

[Shaojin Wen]

> Improve the performance of UUID::toString by using Long.expand and SWAR (SIMD within a register) instead of table lookup. Eliminating the table lookup can also avoid the performance degradation problem when the cache misses.

Shaojin Wen has updated the pull request incrementally with two additional commits since the last revision:

 - add comments, from @j3graham
 - fix comments, from @j3graham

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Changes:
  - all: https://git.openjdk.org/jdk/pull/22928/files
  - new: https://git.openjdk.org/jdk/pull/22928/files/3b94f81f..61e3faee

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22928&range=06
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22928&range=05-06

  Stats: 3 lines in 1 file changed: 2 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/22928.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22928/head:pull/22928

PR: https://git.openjdk.org/jdk/pull/22928