Some systems do not have these types available, and they are simply
convenience aliases. Instead use the expanded versions which are more
portable.
Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=101192
Rework arc4random_stir() and arc4random_addrandom() code over the new
internal API, and documentation in the man page. Adapt the code to the
local build system.
Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=85827