<i18n dev> RFR: 8345668: ZoneOffset.ofTotalSeconds performance regression [v4]

[Naoto Sato]

> The change made in [JDK-8288723](https://bugs.openjdk.org/browse/JDK-8288723) seems innocuous, but it caused this performance regression. Partially reverting the change (ones that involve `computeIfAbsent()`) to the original. Provided a benchmark that iterates the call to `ZoneOffset.ofTotalSeconds(0)` 1,000 times, which improves the operation time from 3,946ns to 2,241ns.

Naoto Sato has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains five additional commits since the last revision:

 - Addresses review comments
 - Merge branch 'master' into JDK-8345668-ofTotalSeconds-perf-regression
 - Fixed compile error
 - Update src/java.base/share/classes/java/time/ZoneOffset.java
   
   Co-authored-by: Roger Riggs <Roger.Riggs at Oracle.com>
 - initial commit

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/22854/files
  - new: https://git.openjdk.org/jdk/pull/22854/files/8dca103a..4dac7bac

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22854&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22854&range=02-03

  Stats: 15609 lines in 368 files changed: 12421 ins; 1981 del; 1207 mod
  Patch: https://git.openjdk.org/jdk/pull/22854.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22854/head:pull/22854

PR: https://git.openjdk.org/jdk/pull/22854