/usr/share/doc/libsuperlu-dev/tests/MATGEN/slu_Cnames.h is in libsuperlu3-dev 3.0+20070106-3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libsuperlu-dev/tests/MATGEN/../../SRC/slu_Cnames.h