re PR other/24829 (libobjc testsuite failures)

	PR other/24829
	PR target/24831
	* gthr-dce.h: Do not gthrw-ify pthread_once_init,
	pthread_key_delete.  From John David Anglin.  gthrw-ify
	pthread_getunique_np only if it it's not a macro.  Delete
	UNUSED macro.
	(__gthread_objc_condition_allocate, __gthread_objc_condition_deallocate,
	__gthread_objc_condition_wait, __gthread_objc_condition_broadcast,
	__gthread_objc_condition_signal, __gthread_key_delete): Add
	"__attribute__ ((__unused__))" to unused arguments.
	(__gthread_recursive_mutex_init_function): Add missing return.
	* gthr-dce.h, gthr-tpf.h, gthr-solaris.h, gthr-posix.h,
	gthr-posix95.h: Use macro-based approach for name redirection
	on targets missing weakref.

From-SVN: r110278