Enable ipa-cp cloning for cold wrappers of hot functions

Enable ipa-cp cloning for cold wrappers of hot functions

ipa-cp cloning disables itself for all functions not passing opt_for_fn
(node->decl, optimize_size) which disables it for cold wrappers of hot
functions where we want to propagate.  Since we later want to time saved
to be considered hot, we do not need to make this early test.

The patch also fixes few other places where AFDO 0 disables ipa-cp.

gcc/ChangeLog:

	* ipa-cp.cc (cs_interesting_for_ipcp_p): Handle
	correctly GLOBAL0 afdo counts.
	(ipcp_cloning_candidate_p): Do not rule out nodes
	!node->optimize_for_size_p ().
	(good_cloning_opportunity_p): Handle afdo counts
	as non-zero.