/usr/bin/amd64-mingw32msvc-dlltool is in mingw32-binutils 2.25-5+5.2+deb8u1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/bin/x86_64-w64-mingw32-dlltool
/usr/bin/x86_64-w64-mingw32-dlltool