tree-optimization/113385 - wrong loop father with early exit vectorization

The following avoids splitting an edge before redirecting it.  This
allows the loop father of the new block to be correct in the first
place.

	PR tree-optimization/113385
	* tree-vect-loop-manip.cc (slpeel_tree_duplicate_loop_to_edge_cfg):
	First redirect, then split the exit edge.