/usr/x86_64-w64-mingw32/bin/readelf is in binutils-mingw-w64-x86-64 2.30-7ubuntu1+8ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/x86_64-w64-mingw32/bin/../../bin/x86_64-w64-mingw32-readelf