This patch, similar to d92739713c, embeds the
`LinuxSeccomp` type of the runtime-spec, so that we can support all options
provided by the spec, and decorates it with our own fields.
With this, profiles can make use of the recently added "Flags" field, to
specify flags that must be passed to seccomp(2) when installing the filter.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>