* cgraph.c (cgraph_edge_cannot_lead_to_return): Also check
	if caller is noreturn.
	* ipa-reference.c (analyze_function): Use ipa_ref_cannot_lead_to_return
	* ipa-ref.h (ipa_ref_cannot_lead_to_return): New function.
	* ipa-ref.c (ipa_ref_cannot_lead_to_return): New function.
	* ipa-pure-const.c (check_decl): Add IPA parameter.
	(state_from_flags): New function.
	(better_state, worse_state): New functions.
	(check_call): When in IPA mode, do not care about callees.
	(check_load, check_store): Update.
	(check_ipa_load, check_ipa_store): New.
	(check_stmt): When in IPA mode, use IPA checkers.
	(analyze_function): Use state_from_flags.
	(propagate): Check indirect edges and references.

From-SVN: r160380