git: openjdk/jdk8u-dev: 8305815: Update Libpng to 1.6.39

[Martin Balao]

Changeset: f4260a4d
Author:    Martin Balao <mbalao at openjdk.org>
Date:      2023-09-26 00:01:11 +0000
URL:       https://git.openjdk.org/jdk8u-dev/commit/f4260a4deed5210fc56f08774e8ca50cf6f7cc8e

8305815: Update Libpng to 1.6.39

Reviewed-by: phh, andrew
Backport-of: c1f759e9d01d646eac69442452151b0467eab306

! THIRD_PARTY_README
! corba/THIRD_PARTY_README
! hotspot/THIRD_PARTY_README
! jaxp/THIRD_PARTY_README
! jaxws/THIRD_PARTY_README
! jdk/THIRD_PARTY_README
! jdk/src/share/native/sun/awt/libpng/CHANGES
! jdk/src/share/native/sun/awt/libpng/LICENSE
! jdk/src/share/native/sun/awt/libpng/README
! jdk/src/share/native/sun/awt/libpng/png.c
! jdk/src/share/native/sun/awt/libpng/png.h
! jdk/src/share/native/sun/awt/libpng/pngconf.h
! jdk/src/share/native/sun/awt/libpng/pnglibconf.h
! jdk/src/share/native/sun/awt/libpng/pngpriv.h
! jdk/src/share/native/sun/awt/libpng/pngrutil.c
! langtools/THIRD_PARTY_README
! nashorn/THIRD_PARTY_README