/usr/lib/gcc-cross/mips64el-linux-gnuabi64/5.5.0 is in gcc-5-mips64el-linux-gnuabi64-base 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