/usr/bin/x86_64-linux-gnux32-gnatgcc is in gnat-8-x86-64-linux-gnux32 8-20180414-1ubuntu2cross1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/bin/x86_64-linux-gnux32-gcc-8
/usr/bin/x86_64-linux-gnux32-gcc-8