RFR: 8339699: Optimize DataOutputStream writeUTF [v2]

[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:

  code style

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Changes:
  - all: https://git.openjdk.org/jdk/pull/20886/files
  - new: https://git.openjdk.org/jdk/pull/20886/files/30786c27..a04b2c34

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20886&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20886&range=00-01

  Stats: 3 lines in 1 file changed: 0 ins; 0 del; 3 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