return auto_vec from get_loop_hot_path

This ensures callers take ownership of the returned vector.

Signed-off-by: Trevor Saunders <tbsaunde@tbsaunde.org>

gcc/ChangeLog:

	* cfgloop.h (get_loop_hot_path): Return auto_vec<basic_block>.
	* cfgloopanal.c (get_loop_hot_path): Likewise.
	* tree-ssa-loop-ivcanon.c (tree_estimate_loop_size): Likewise.
3 files changed