8372977: Unnecessary gthread-2.0 loading

[GoeLin]

I backport this for parity with 21.0.11-oracle.

Update: The clean backport breaks the build. There are two gtk implementations in
OpenJDK 21: gtk2 and gtk3. This change adresses gtk3, see description in
original JBS issue. Gtk2 was removed in 8329471: "Remove GTK2" in 24.

Gtk2 implements the same functions as gtk3, so we can not remove
the decls in the header. See second commit.

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Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8372977 needs maintainer approval

Issue

• JDK-8372977: Unnecessary gthread-2.0 loading (Bug - P3 - Requested)

Reviewers

• Ralf Schmelter (@schmelter-sap - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk21u-dev.git pull/2515/head:pull/2515
$ git checkout pull/2515

Update a local copy of the PR:
$ git checkout pull/2515
$ git pull https://git.openjdk.org/jdk21u-dev.git pull/2515/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 2515

View PR using the GUI difftool:
$ git pr show -t 2515

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk21u-dev/pull/2515.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back goetz! A progress list of the required criteria for merging this PR into master 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.

[openjdk]

⚠️ @GoeLin 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.

[mlbridge]

Webrevs

• 01: Full - Incremental (daa3ad0c)
• 00: Full (4a3edc3b)

[schmelter-sap]

Looks good.