qemu: factor out event notification / rearm alarm timer on main_loop_wait (Marcelo...

qemu: factor out event notification / rearm alarm timer on main_loop_wait (Marcelo Tosatti)

Special events that have no particular event descriptor (either fd for UNIX
or HANDLE for Windows) associated with make use of an artificial one.

Factor the alarm timer notification so that it can be used for other events,
and move dyntick timer rearm to main_loop_wait.

aliguori: made sure to return a value in qemu_event_init() on win32

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@7240 c046a42c-6fe2-441c-8c8c-71466251a162