[PATCH x4: hurd] - Almost fixing the rumpdisk stat issue

[Damien Zammit]

Hi,

[PATCH 1/4] startup: Mark all essential tasks as our children
This patch loops through the processes and determines which ones are
important, and then marks them as child processes of startup.

[PATCH 2/4] libmachdev: Add proc_set_arg_locations
I'm not sure if this patch is needed.

[PATCH 3/4] proc: Follow p_parent to root for checking startup
This exposes a strange issue that may be fixed with this patch.

[PATCH 4/4] procfs: Add debug for failing EIO
This is a debug mach_print that highlights the bug we want to fix
with rumpdisk (cat /proc/6/stat) failing on EIO.

Damien