logilab-astng #48038 handle new Raising exceptions [open]

The _ast node has now fields 'exc', 'cause' instead of 'type', 'inst', 'tback'

The meaning of this nodes are quite different, so maybe we should have in 3.x different Raise node attributes

prioritynormal
typetask
done in<not specified>
load2.000
load left1.000
closed by<not specified>