/usr/lib/gcc-cross/mips-linux-gnu/6/ecj1 is in gcj-6-mips-linux-gnu 6.3.0-18cross1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/gcc-cross/mips-linux-gnu/6/../../../x86_64-linux-gnu/gcc/ecj1