hurd: Reimplement libc locks using mach's gsync

hurd: Reimplement libc locks using mach's gsync

	* hurd/Makefile (routines): Add hurdlock.
	* hurd/Versions (GLIBC_PRIVATE): Added new entry to export the above
	interface.
	(HURD_CTHREADS_0.3): Remove __libc_getspecific.
	* hurd/hurdpid.c: Include <lowlevellock.h>
	(_S_msg_proc_newids): Use lll_wait to synchronize.
	* hurd/hurdsig.c: (reauth_proc): Use __mutex_lock and __mutex_unlock.
	* hurd/setauth.c: Include <hurdlock.h>, use integer for synchronization.
	* mach/Makefile (lock-headers): Remove machine-lock.h.
	* mach/lock-intern.h: Include <lowlevellock.h> instead of
	<machine-lock.h>.
	(__spin_lock_t): New type.
	(__SPIN_LOCK_INITIALIZER): New macro.
	(__spin_lock, __spin_unlock, __spin_try_lock, __spin_lock_locked,
	__mutex_init, __mutex_lock_solid, __mutex_unlock_solid, __mutex_lock,
	__mutex_unlock, __mutex_trylock): Use lll to implement locks.
	* mach/mutex-init.c: Include <lowlevellock.h> instead of <cthreads.h>.
	(__mutex_init): Initialize with lll.
	* manual/errno.texi (EOWNERDEAD, ENOTRECOVERABLE): New errno values.
	* sysdeps/mach/Makefile: Add libmachuser as dependencies for libs
	needing lll.
	* sysdeps/mach/hurd/bits/errno.h: Regenerate.
	* sysdeps/mach/hurd/cthreads.c (__libc_getspecific): Remove function.
	* sysdeps/mach/hurd/bits/libc-lock.h: Remove file.
	* sysdeps/mach/hurd/setpgid.c: Include <lowlevellock.h>.
	(__setpgid): Use lll for synchronization.
	* sysdeps/mach/hurd/setsid.c: Likewise with __setsid.
	* sysdeps/mach/bits/libc-lock.h: Include <tls.h> and <lowlevellock.h>
	instead of <cthreads.h>.
	(_IO_lock_inexpensive): New macro
	(__libc_lock_recursive_t, __rtld_lock_recursive_t): New structures.
	(__libc_lock_self0): New declaration.
	(__libc_lock_owner_self): New macro.
	(__libc_key_t): Remove type.
	(_LIBC_LOCK_INITIALIZER): New macro.
	(__libc_lock_define_initialized, __libc_lock_init, __libc_lock_fini,
	__libc_lock_fini_recursive, __rtld_lock_fini_recursive,
	__libc_lock_lock, __libc_lock_trylock, __libc_lock_unlock,
	__libc_lock_define_initialized_recursive,
	__rtld_lock_define_initialized_recursive,
	__libc_lock_init_recursive, __libc_lock_trylock_recursive,
	__libc_lock_lock_recursive, __libc_lock_unlock_recursive,
	__rtld_lock_initialize, __rtld_lock_trylock_recursive,
	__rtld_lock_lock_recursive, __rtld_lock_unlock_recursive
	__libc_once_define, __libc_mutex_unlock): Reimplement with lll.
	(__libc_lock_define_recursive, __rtld_lock_define_recursive,
	_LIBC_LOCK_RECURSIVE_INITIALIZER, _RTLD_LOCK_RECURSIVE_INITIALIZER):
	New macros.
	Include <libc-lockP.h> to reimplement libc_key* with pthread_key*.
	* hurd/hurdlock.c: New file.
	* hurd/hurdlock.h: New file.
	* mach/lowlevellock.h: New file