/usr/bin/mips64-linux-gnuabi64-gcc is in gcc-mips64-linux-gnuabi64 4:5.3.1-1ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/bin/mips64-linux-gnuabi64-gcc-5
/usr/bin/mips64-linux-gnuabi64-gcc-5