8381379: Support std/dstOffset attributes in CLDR's metazone definitions

[gnu-andrew]

This backports support for the dstOffset attribute to the CLDR converter, which is necessary to support new timezone changes in Vancouver (tzdata2026b) and Alberta (tzdata2026c) correctly.

As there are no dstOffset attributes currently in the CLDR data in 25u (version 47), this doesn't yet do much. The test for it will be writing a fix for JDK-8390388: "Cherry-pick tz attributes from newer CLDR data for jdk25u and earlier" which doesn't exist for 27 as it has the newer CLDR with dstOffset.

I actually thought the TimeZoneNamesTest.java changes here might fail without first having the attributes, but this was not the case. So this and its dependency #756 should be able to go in nearly clean and then we get to the more tricky but interesting part. The test passes because of:

+            // This needs to change once TZDB adopts -7 offset year round, and CLDR uses explicit dst offset
+            // namely, "Pacific Standard Time" -> "Pacific Daylight Time"
+            Arguments.of(ZonedDateTime.of(2026, 12, 5, 0, 0, 0, 0, ZoneId.of("America/Vancouver")), "Pacific Standard Time")

which is changed in JDK-8371842: Update CLDR to Version 48.2, which we'll need to backport hunks of for JDK-8390388. With that change & tzdata 2026b (already in 25u), Vancouver should still be reporting "Pacific Daylight Time" in December.

The only adjustments were the copyright header on DateTimeFormatterBuilder.java and the bug ID placement on test/jdk/sun/util/resources/cldr/TimeZoneNamesTest.java, due to 8382020 & 8384043 going in first for the last tzdata update. As it stands, all tests pass as on the previous PR:

$ make -C $HOME/builder/25u-dev run-test TEST="jdk/sun/util/resources"
...
==============================
Test summary
==============================
   TEST                                              TOTAL  PASS  FAIL ERROR  SKIP   
   jtreg:test/jdk/sun/util/resources                    22    22     0     0     0   
==============================
TEST SUCCESS

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Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• JDK-8381379 needs maintainer approval
• Change must not contain extraneous whitespace
• Commit message must refer to an issue

Issue

• JDK-8381379: Support std/dstOffset attributes in CLDR's metazone definitions (Enhancement - P4)

Reviewers

• Goetz Lindenmaier (@GoeLin - Reviewer) 🔄 Re-review required (review applies to 01431d16)
• Severin Gehwolf (@jerboaa - Reviewer) 🔄 Re-review required (review applies to 01431d16)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk25u-dev.git pull/757/head:pull/757
$ git checkout pull/757

Update a local copy of the PR:
$ git checkout pull/757
$ git pull https://git.openjdk.org/jdk25u-dev.git pull/757/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 757

View PR using the GUI difftool:
$ git pr show -t 757

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk25u-dev/pull/757.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back andrew! A progress list of the required criteria for merging this PR into pr/756 will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

❗ This change is not yet ready to be integrated.
See the Progress checklist in the description for automated requirements.

[openjdk]

This backport pull request has now been updated with issue from the original commit.

[mlbridge]

Webrevs

• 02: Full - Incremental (454056f3)
• 01: Full - Incremental (01431d16)
• 00: Full (01431d16)

[GoeLin]

LGTM
Yes, only minor changes.
I ran it through our nightly testing which is green, but as stated it's probably not really tested as not yet used.

[jerboaa]

Looks OK.

[openjdk-notifier]

The parent pull request that this pull request depends on has now been integrated and the target branch of this pull request has been updated. This means that changes from the dependent pull request can start to show up as belonging to this pull request, which may be confusing for reviewers. To remedy this situation, simply merge the latest changes from the new target branch into this pull request by running commands similar to these in the local repository for your personal fork:

git checkout JDK-8381379-25u
git fetch https://git.openjdk.org/jdk25u-dev.git master
git merge FETCH_HEAD
# if there are conflicts, follow the instructions given by git merge
git commit -m "Merge master"
git push

[openjdk]

⚠️ @gnu-andrew This change is now ready for you to apply for maintainer approval. This can be done directly in each associated issue or by using the /approval command.

[openjdk]

@gnu-andrew Please do not rebase or force-push to an active PR as it invalidates existing review comments. Note for future reference, the bots always squash all changes into a single commit automatically as part of the integration. See OpenJDK Developers’ Guide for more information.

[gnu-andrew]

Just waiting on re-reviews but patch should be identical to before (git just dropped the dependency commit that has been rebased and pushed upstream by Skara)