hg: jdk8u/jdk8u-dev/jdk: 8230597: Update GIFlib library to the 5.2.1

[sgehwolf at redhat.com]

Changeset: 803e5988795f
Author:    serb
Date:      2019-12-02 16:38 -0800
URL:       https://hg.openjdk.java.net/jdk8u/jdk8u-dev/jdk/rev/803e5988795f

8230597: Update GIFlib library to the 5.2.1
Reviewed-by: prr, psadhukhan, jdv

! THIRD_PARTY_README
! src/share/native/sun/awt/giflib/dgif_lib.c
! src/share/native/sun/awt/giflib/gif_err.c
! src/share/native/sun/awt/giflib/gif_hash.h
! src/share/native/sun/awt/giflib/gif_lib.h
! src/share/native/sun/awt/giflib/gif_lib_private.h
! src/share/native/sun/awt/giflib/gifalloc.c
! src/share/native/sun/awt/giflib/openbsd-reallocarray.c