RFR: 8333833: UUID toString removes the use of ByteArrayLittleEndian [v3]

[Shaojin Wen]

> After PR #16245, C2 optimizes stores into primitive arrays by combining values ​​into larger stores. In the UUID.toString method, ByteArrayLittleEndian can be removed, making the code more elegant and faster.

Shaojin Wen has updated the pull request incrementally with one additional commit since the last revision:

  change method name, putHex -> putHex4, and fix comments

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Changes:
  - all: https://git.openjdk.org/jdk/pull/19610/files
  - new: https://git.openjdk.org/jdk/pull/19610/files/ace7a9f6..d6b4ed25

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=19610&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=19610&range=01-02

  Stats: 12 lines in 2 files changed: 1 ins; 0 del; 11 mod
  Patch: https://git.openjdk.org/jdk/pull/19610.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19610/head:pull/19610

PR: https://git.openjdk.org/jdk/pull/19610