Assimp 4.1 changes break compilation with gcc-7.3.0

In file included from /mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.c:14:0:
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.h:38:44: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'OF'
typedef voidpf (ZCALLBACK *open_file_func) OF((voidpf opaque, const char* filename, int mode));
^~
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.h:39:44: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'OF'
typedef uLong (ZCALLBACK *read_file_func) OF((voidpf opaque, voidpf stream, void* buf, uLong size));
^~
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.h:40:45: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'OF'
typedef uLong (ZCALLBACK *write_file_func) OF((voidpf opaque, voidpf stream, const void* buf, uLong size));
^~
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.h:41:44: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'OF'
typedef long (ZCALLBACK *tell_file_func) OF((voidpf opaque, voidpf stream));
^~
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.h:42:44: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'OF'
typedef long (ZCALLBACK *seek_file_func) OF((voidpf opaque, voidpf stream, uLong offset, int origin));
^~
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.h:43:45: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'OF'
typedef int (ZCALLBACK *close_file_func) OF((voidpf opaque, voidpf stream));
^~
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.h:44:49: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'OF'
typedef int (ZCALLBACK *testerror_file_func) OF((voidpf opaque, voidpf stream));
^~
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.h:48:5: error: unknown type name 'open_file_func'
open_file_func zopen_file;
^~~~~~~~~~~~~~
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.h:49:5: error: unknown type name 'read_file_func'
read_file_func zread_file;
^~~~~~~~~~~~~~
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.h:50:5: error: unknown type name 'write_file_func'
write_file_func zwrite_file;
^~~~~~~~~~~~~~~
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.h:51:5: error: unknown type name 'tell_file_func'
tell_file_func ztell_file;
^~~~~~~~~~~~~~
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.h:52:5: error: unknown type name 'seek_file_func'
seek_file_func zseek_file;
^~~~~~~~~~~~~~
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.h:53:5: error: unknown type name 'close_file_func'
close_file_func zclose_file;
^~~~~~~~~~~~~~~
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.h:54:5: error: unknown type name 'testerror_file_func'
testerror_file_func zerror_file;
^~~~~~~~~~~~~~~~~~~
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.h:60:26: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'OF'
void fill_fopen_filefunc OF((zlib_filefunc_def* pzlib_filefunc_def));
^~
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.c:32:34: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'OF'
voidpf ZCALLBACK fopen_file_func OF((
^~
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.c:37:33: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'OF'
uLong ZCALLBACK fread_file_func OF((
^~
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.c:43:34: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'OF'
uLong ZCALLBACK fwrite_file_func OF((
^~
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.c:49:32: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'OF'
long ZCALLBACK ftell_file_func OF((
^~
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.c:53:32: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'OF'
long ZCALLBACK fseek_file_func OF((
^~
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.c:59:32: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'OF'
int ZCALLBACK fclose_file_func OF((
^~
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.c:63:32: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'OF'
int ZCALLBACK ferror_file_func OF((
^~
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.c: In function 'fill_fopen_filefunc':
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.c:169:36: warning: assignment makes integer from pointer without a cast [-Wint-conversion]
pzlib_filefunc_def->zopen_file = fopen_file_func;
^
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.c:170:36: warning: assignment makes integer from pointer without a cast [-Wint-conversion]
pzlib_filefunc_def->zread_file = fread_file_func;
^
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.c:171:37: warning: assignment makes integer from pointer without a cast [-Wint-conversion]
pzlib_filefunc_def->zwrite_file = fwrite_file_func;
^
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.c:172:36: warning: assignment makes integer from pointer without a cast [-Wint-conversion]
pzlib_filefunc_def->ztell_file = ftell_file_func;
^
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.c:173:36: warning: assignment makes integer from pointer without a cast [-Wint-conversion]
pzlib_filefunc_def->zseek_file = fseek_file_func;
^
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.c:174:37: warning: assignment makes integer from pointer without a cast [-Wint-conversion]
pzlib_filefunc_def->zclose_file = fclose_file_func;
^
/mnt/gentoo/home/herb/src/qt/qt5.x-src/qt3d/src/3rdparty/assimp/contrib/unzip/ioapi.c:175:37: warning: assignment makes integer from pointer without a cast [-Wint-conversion]
pzlib_filefunc_def->zerror_file = ferror_file_func;
^
make[4]: *** [Makefile:11466: .obj/ioapi.o] Error 1
make[4]: Leaving directory '/mnt/gentoo/home/herb/src/qt/qt5.x-build/qt3d/src/plugins/sceneparsers/assimp'
make[3]: *** [Makefile:47: sub-assimp-make_first] Error 2
make[3]: Leaving directory '/mnt/gentoo/home/herb/src/qt/qt5.x-build/qt3d/src/plugins/sceneparsers'
make[2]: *** [Makefile:247: sub-plugins-sceneparsers-make_first] Error 2
make[2]: Leaving directory '/mnt/gentoo/home/herb/src/qt/qt5.x-build/qt3d/src'
make[1]: *** [Makefile:48: sub-src-make_first] Error 2
make[1]: Leaving directory '/mnt/gentoo/home/herb/src/qt/qt5.x-build/qt3d'
make: *** [Makefile:600: module-qt3d-make_first] Error 2