/usr/powerpc-linux-gnu/lib64/libobjc.so.4 is in lib64objc4-powerpc-cross 8-20180414-1ubuntu2cross1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/powerpc-linux-gnu/lib64/libobjc.so.4.0.0
/usr/powerpc-linux-gnu/lib64/libobjc.so.4.0.0