Function create_namespace_object 

pub(crate) fn create_namespace_object<D: DomTypes>(
    cx: JSContext,
    global: HandleObject<'_>,
    proto: HandleObject<'_>,
    class: &'static NamespaceObjectClass,
    methods: &[Guard<&'static [JSFunctionSpec]>],
    constants: &[Guard<&'static [ConstantSpec]>],
    name: &CStr,
    rval: MutableHandleObject<'_>,
)

Create a new namespace object.