/usr/sh4-linux-gnu/lib/libpthread.so.0 is in libc6-sh4-cross 2.23-0ubuntu3cross1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/sh4-linux-gnu/lib/libpthread-2.23.so
/usr/sh4-linux-gnu/lib/libpthread-2.23.so