2017-11-14  Richard Biener  <rguenther@suse.de>

	* tree-cfgcleanup.c (cleanup_control_expr_graph): Remove first_p
	paramter and handling.
	(cleanup_control_flow_bb): Likewise.
	(cleanup_control_flow_pre): New helper performing a DFS walk
	to call cleanup_control_flow_bb in PRE order.
	(cleanup_tree_cfg_1): Do the first phase of cleanup_control_flow_bb
	via cleanup_control_flow_pre.

From-SVN: r254730