RFR: 8346944: Update Unicode Data Files to 17.0.0 [v2]

[Justin Lu]

On Mon, 17 Nov 2025 19:15:50 GMT, Naoto Sato <naoto at openjdk.org> wrote:

>> Updates the JDK to use the latest Unicode 17.0.0, which also updates the ICU4J along with it ([8346947](https://bugs.openjdk.org/browse/JDK-8346947)
>> Update ICU4J to Version 78.1). The corresponding CSR has already been approved.
>
> 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 11 additional commits since the last revision:
> 
>  - Merge branch 'master' into JDK-8346944-Unicode-17
>  - icudata path fix
>  - Update versions
>  - icu4j final
>  - .md file changes
>  - 17.0 final
>  - icudata78b(binary)
>  - CaseFolding.text -> 17, copyright symbol as is
>  - icudt78b
>  - 17-beta
>  - ... and 1 more: https://git.openjdk.org/jdk/compare/40595ac9...088cdaea

lgtm. (Looks like I missed integration by a few minutes; perhaps my comment can go into Unicode 18)

src/java.base/share/classes/java/lang/Character.java line 746:

> 744:     public static final class UnicodeBlock extends Subset {
> 745:         /**
> 746:          * NUM_ENTITIES should match the total number of UnicodeBlocks.

I thought at first `NUM_ENTITIES` should be 790 due to 8 new `UnicodeBlock`s being added. However, it does go up to 804, becasue the total number includes the identifiers _and_ aliases (which is still a single `UnicodeBlock`). I think that distinction is worth correcting in the comment.

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

PR Review: https://git.openjdk.org/jdk/pull/28093#pullrequestreview-3479235676
PR Review Comment: https://git.openjdk.org/jdk/pull/28093#discussion_r2539282547