bb-reorder.c (sanitize_hot_paths): Release hot_bbs_to_check.

2018-05-04  Richard Biener  <rguenther@suse.de>

	* bb-reorder.c (sanitize_hot_paths): Release hot_bbs_to_check.
	* gimple-ssa-store-merging.c
	(imm_store_chain_info::output_merged_store): Remove redundant create,
	release split_store vector contents on failure.
	* tree-vect-slp.c (vect_schedule_slp_instance): Avoid leaking
	scalar stmt vector on cache hit.

From-SVN: r259932