* flow.c (try_simplify_condjump): Avoid duplicated edges.

	* flow.c (try_simplify_condjump): Avoid duplicated edges.
	(verify_flow_info): Check for duplicated edges; clarify
	error reporting.

	* flow.c (block_label): Update basic_block_for_insn.
	(commit_edge_insertions): Call compute_bb_for_insn.

	* flow.c (purge_dead_edges): Handle conditional jumps and conditional
	returns too.

	* flow.c (redirect_edge_and_branch,
	try_optimize_cfg): Use redirect_edge_succ_nodup
	(redirect_edge_succ_nodup): New.
	* basic_block.h (redirect_edge_succ_nodup): Declare.

	* toplev.c (rest_of_compilation): Rebuild CFG before cfg_cleanup
	after gcse.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@44320 138bc75d-0d04-0410-961f-82ee72b054a4