synch with TL 38104

source/build-aux/config.sub

source/build-aux/texinfo.tex

source/libs/README

source/libs/libpng/ChangeLog

source/libs/libpng/configure

source/libs/libpng/libpng-1.6.17/ANNOUNCE

source/libs/libpng/libpng-1.6.18-PATCHES/ChangeLog

source/libs/libpng/libpng-1.6.18-PATCHES/TL-Changes

source/libs/libpng/libpng-1.6.18/ANNOUNCE

source/libs/libpng/libpng-1.6.18/CHANGES

source/libs/libpng/libpng-1.6.18/CMakeLists.txt

source/libs/libpng/libpng-1.6.18/INSTALL

source/libs/libpng/libpng-1.6.18/LICENSE

source/libs/libpng/libpng-1.6.18/Makefile.am

source/libs/libpng/libpng-1.6.18/README

source/libs/libpng/libpng-1.6.18/TODO

source/libs/libpng/libpng-1.6.18/arm/arm_init.c

source/libs/libpng/libpng-1.6.18/arm/filter_neon.S

...ce/libs/libpng/libpng-1.6.18/arm/filter_neon_intrinsics.c

source/libs/libpng/libpng-1.6.18/autogen.sh