re PR tree-optimization/91257 (Compile-time and memory-hog hog)

re PR tree-optimization/91257 (Compile-time and memory-hog hog)

2019-07-29  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/91257
	* tree-ssa-sccvn.h (struct vn_avail): New.
	(struct vn_ssa_aux): Add avail member.
	* tree-ssa-sccvn.c (class rpo_elim): Remove m_rpo_avail
	member, add m_avail_freelist one.
	(rpo_elim::~rpo_elim): Remove.
	(rpo_elim::eliminate_avail): Adjust to new avail tracking
	data structure.
	(rpo_elim::eliminate_push_avail): Likewise.
	(do_unwind): Likewise.
	(do_rpo_vn): Likewise.

From-SVN: r273877