[PATCH v8 0/2 hurd] Add irqhelp and clean up ddekit

[Damien Zammit]

Hi,

I think we need to allow the irq handler to be called one more time,
because we don't know if there is a pending interrupt until we need
to handle one.  Once we enable the irq one more time, it is necessary
to handle the last interrupt before quitting the handler.

I tested this behaviour and it works on netdde.static to ifup and ifdown,
and send a large file over ssh.

Damien