tree-cfg.c (group_case_labels_stmt): Return whether we changed anything.

tree-cfg.c (group_case_labels_stmt): Return whether we changed anything.

2017-06-29  Richard Biener  <rguenther@suse.de>

	* tree-cfg.c (group_case_labels_stmt): Return whether we changed
	anything.
	(group_case_labels): Likewise.
	(find_taken_edge): Push sanity checking on val to workers...
	(find_taken_edge_cond_expr): ... here
	(find_taken_edge_switch_expr): ... and here, handle cases
	with just a default label.
	* tree-cfg.h (group_case_labels_stmt): Adjust prototype.
	(group_case_labels): Likewise.
	* tree-cfgcleanup.c (execute_cleanup_cfg_post_optimizing): When
	group_case_labels does anything cleanup the CFG again.

From-SVN: r249780