Fix PTA info in IPA ICF (PR ipa/84658).

Fix PTA info in IPA ICF (PR ipa/84658).

2018-03-13  Martin Liska  <mliska@suse.cz>

	PR ipa/84658.
	* (sem_item_optimizer::sem_item_optimizer): Initialize new
	vector.
	(sem_item_optimizer::~sem_item_optimizer): Release it.
	(sem_item_optimizer::merge_classes): Register variable aliases.
	(sem_item_optimizer::fixup_pt_set): New function.
	(sem_item_optimizer::fixup_points_to_sets): Likewise.
	* ipa-icf.h: Declare new variables and functions.
2018-03-13  Martin Liska  <mliska@suse.cz>

	PR ipa/84658.
	* g++.dg/ipa/pr84658.C: New test.

From-SVN: r258480