/usr/share/xen-tools/dapper.d/15-disable-hwclock is in xen-tools 4.4-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/xen-tools/dapper.d/../common/15-disable-hwclock
/usr/share/xen-tools/dapper.d/../common/15-disable-hwclock