/usr/lib/gcc-cross/mips64el-linux-gnuabi64/5/32/libobjc.so is in lib32objc-5-dev-mips64el-cross 5.5.0-12ubuntu1cross1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/gcc-cross/mips64el-linux-gnuabi64/5/32/../../../../../mips64el-linux-gnuabi64/libo32/libobjc.so.4