vec: use auto_vec in a few more places

vec: use auto_vec in a few more places

The uses of vec<T> in get_all_loop_exits and process_conditional were memory
leaks, as .release() was never called for them.  The other changes are some
cases that did have proper release handling, but it's simpler to leave
releasing to the auto_vec destructor.

gcc/ChangeLog:

	* sel-sched-ir.h (get_all_loop_exits): Use auto_vec.

gcc/cp/ChangeLog:

	* class.c (struct find_final_overrider_data): Use auto_vec.
	(find_final_overrider): Remove explicit release.
	* coroutines.cc (process_conditional): Use auto_vec.
	* cp-gimplify.c (struct cp_genericize_data): Use auto_vec.
	(cp_genericize_tree): Remove explicit release.
	* parser.c (cp_parser_objc_at_property_declaration): Use
	auto_delete_vec.
	* semantics.c (omp_reduction_lookup): Use auto_vec.