hg: jdk/submit13: 8217676: Upgrade libpng to 1.6.37

[sergey.bylokhov at oracle.com]

Changeset: 53154e45385a
Author:    serb
Date:      2019-06-12 13:50 -0700
URL:       https://hg.openjdk.java.net/jdk/submit13/rev/53154e45385a

8217676: Upgrade libpng to 1.6.37
Reviewed-by: prr, jdv, kcr

! make/lib/Awt2dLibraries.gmk
! src/java.desktop/share/legal/libpng.md
! src/java.desktop/share/native/libsplashscreen/libpng/CHANGES
! src/java.desktop/share/native/libsplashscreen/libpng/LICENSE
! src/java.desktop/share/native/libsplashscreen/libpng/README
! src/java.desktop/share/native/libsplashscreen/libpng/png.c
! src/java.desktop/share/native/libsplashscreen/libpng/png.h
! src/java.desktop/share/native/libsplashscreen/libpng/pngconf.h
! src/java.desktop/share/native/libsplashscreen/libpng/pngdebug.h
! src/java.desktop/share/native/libsplashscreen/libpng/pngerror.c
! src/java.desktop/share/native/libsplashscreen/libpng/pngget.c
! src/java.desktop/share/native/libsplashscreen/libpng/pnginfo.h
! src/java.desktop/share/native/libsplashscreen/libpng/pnglibconf.h
! src/java.desktop/share/native/libsplashscreen/libpng/pngmem.c
! src/java.desktop/share/native/libsplashscreen/libpng/pngpread.c
! src/java.desktop/share/native/libsplashscreen/libpng/pngpriv.h
! src/java.desktop/share/native/libsplashscreen/libpng/pngread.c
! src/java.desktop/share/native/libsplashscreen/libpng/pngrio.c
! src/java.desktop/share/native/libsplashscreen/libpng/pngrtran.c
! src/java.desktop/share/native/libsplashscreen/libpng/pngrutil.c
! src/java.desktop/share/native/libsplashscreen/libpng/pngset.c
! src/java.desktop/share/native/libsplashscreen/libpng/pngstruct.h
! src/java.desktop/share/native/libsplashscreen/libpng/pngtrans.c