* cgraph.h (cgraph_node_cannot_return,
	cgraph_edge_cannot_lead_to_return): New functions.
	* cgraph.c (cgraph_node_cannot_return,
	cgraph_edge_cannot_lead_to_return): Use them.
	* ipa-pure-const.c (pure_const_names): New static var.
	(check_call): Handle calls not leading to return.
	(pure_const_read_summary): Dump info read.
	(propagate): Dump info about propagation process; ignore side
	effects of functions not leading to exit; fix handling of
	pure functions.

From-SVN: r160051