RFR: 8339699: Optimize DataOutputStream writeUTF [v5]

[Shaojin Wen]

> PR #20772 introduced an optimization for writeUTF, which can also be used in DataOutputStream::writeUTF.

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

  suggestion from @liach

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/20886/files
  - new: https://git.openjdk.org/jdk/pull/20886/files/58a23d4f..83fc4685

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20886&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20886&range=03-04

  Stats: 10 lines in 4 files changed: 3 ins; 0 del; 7 mod
  Patch: https://git.openjdk.org/jdk/pull/20886.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20886/head:pull/20886

PR: https://git.openjdk.org/jdk/pull/20886