8348598: Update Libpng to 1.6.47

[zzambers]

This backport updates bundled libpng to 1.6.47.
There are some differences to jdk11:

• there is no libpng.md in JDK 8, equivalent changes were done to THIRD_PARTY_README
• changes to UPDATING.txt were excluded (this file is not present in 8)
• changes to /lib/Awt2dLibraries.gmk were excluded, as build system of jdk 8 is different and there is no support for DISABLED_WARNINGS_* there

Otherwise, when it comes to library source files (libpng dir), changes applied cleanly (although they have different path).
I have also tried to use diff to compare contents of libpng directory (after update to 1.6.47) in jdk 8 and jdk 11, there are same, except for UPDATING.txt, which is only present in jdk 11.

Motivation:

• to fix one build error on macos-15 (it no longer ships with fp.h)

 In file included from /Users/runner/work/jdk8u-dev/jdk8u-dev/jdk/jdk/src/share/native/sun/awt/libpng/png.c:42:
/Users/runner/work/jdk8u-dev/jdk8u-dev/jdk/jdk/src/share/native/sun/awt/libpng/pngpriv.h:552:16: fatal error: 'fp.h' file not found
  552 | #      include <fp.h>
      |                ^~~~~~
1 error generated.
gmake[2]: *** [lib/Awt2dLibraries.gmk:1256: /Users/runner/work/jdk8u-dev/jdk8u-dev/jdk/build/macos-x64/jdk/objs/libsplashscreen/png.o] Error 1

• to prepare for JDK-8372534 (update to 1.6.51) in the future

Testing:

• testing in GHA: OK (failures of TestCPUAwareness.java are unrelated)

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• JDK-8348598 needs maintainer approval
• JDK-8329004 needs maintainer approval
• JDK-8316030 needs maintainer approval
• Change must not contain extraneous whitespace
• Commit message must refer to an issue

Issues

• JDK-8348598: Update Libpng to 1.6.47 (Bug - P3)
• JDK-8316030: Update Libpng to 1.6.40 (Bug - P3)
• JDK-8329004: Update Libpng to 1.6.43 (Bug - P3)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk8u-dev.git pull/729/head:pull/729
$ git checkout pull/729

Update a local copy of the PR:
$ git checkout pull/729
$ git pull https://git.openjdk.org/jdk8u-dev.git pull/729/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 729

View PR using the GUI difftool:
$ git pr show -t 729

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk8u-dev/pull/729.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back zzambers! 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.

[zzambers]

/issue add 8316030,8329004

[mlbridge]

Webrevs

• 00: Full (3135e422)

[openjdk]

@zzambers
Adding additional issue to issue list: 8316030: Update Libpng to 1.6.40.

Adding additional issue to issue list: 8329004: Update Libpng to 1.6.43.