Changes:
* fixed: pthread_kill() does not restore the critical level when given
signal number is zero.
* New API: POSIX readdir_r.
* fixed: interruption by a signal whose handler is SIG_SIGWAIT_NP may
cause infinite loop.
* fixed: PTL's internal SIGSEGV handler gets strange arguments on a
system that has POSIX-based signal facility.
Changes between PTL2-current-990622 and PTL-2.1.2
* support NetBSD/arm32.
* fix a configure.in bug which fails if $MACHINE != $MACHINE_ARCH.
* src/io_udp.c (send_timedwait, sendto_timedwait,
sendmsg_timedait): While underlying system calls return with
EWOULDBLOCK, continue writing.
* src/signal.c (_pthread_signal_init): On system that PTL can set
the stack pointer without using sigstack(), SIGUSR2 can be used
for user's purpose.
* src/internal.h (END_CRITICAL): fixed: signal interruptions are
lost in certain situation theoretically.
* src/io.c: use O_NONBLOCK rather than O_NDELAY in SunOS5.
* Util/Makefile.in: version number of libPTL.so is changed to 2.0.
* src/specific.c (pthread_key_create, pthread_setspecific): if
fail to allocate the memory, returns ENOMEM.
* src/cond.c, src/mutex.c, include/sys/types.h: pthread_mutex_t
and pthread_cond_t are changed from `pointer to struct' to
`struct'.
* src/cond-attr.c, include/sys/types.h: pthread_condattr_t is
changed from integer handle to struct.
* src/cond.c, src/mutex.c, src/pthread.c:
pthread_{mutex_,cond_,}setname_np returns ENOMEM if malloc()
returns NULL.
* src/cancel.c (pthread_setcancelstate): if FLAG_CLEANUP_HANDLER
is set, do not call pthread_exit() even if PTHREAD_CANCEL_ENABLE
is specified and the thread is already cancel requested.
(pthread_testcancel): similar to above.
* src/internal.h (FLAG_CLEANUP_HANDLER): this flag shows that the
thread is currently executing cleanup handlers.
* src/sched.c (after_csw): Clear FLAG_DO_CANCEL flag before
executing cleanup handlers to prevent entering executing cleanup
handlers loop.
* src/io.c (_pthread_pdb_iostat): Implement `iostat' command into
PDB.
