Hi all,

Small change here to pass the restart status to 
'kill-emacs-query-functions' in 'save-buffers-kill-emacs' so any 
functions there can react to being restarted, sample use-case this may 
be useful is if one is using a package like perspective.el to handle 
buffer/window management and when calling `M-x restart-emacs` you WANT 
your last session to be persisted, but just starting Emacs normally you 
don't.

There are other potential use-cases for this too, so hopefully this 
patch is well-received.

Thanks all,

Ellis (@lkn)