* cygwin.din (pthread_attr_getstack): Export.

* cygwin.din (pthread_attr_getstack): Export.
(pthread_attr_getstackaddr): Export.
(pthread_getattr_np): Export.
* ntdll.h (enum _THREAD_INFORMATION_CLASS): Add ThreadBasicInformation.
(struct _THREAD_BASIC_INFORMATION): Define.
(NtQueryInformationThread): Declare.
* posix.sgml (std-susv4): Add pthread_attr_getstack.
(std-gnu): Add pthread_getattr_np.
(std-deprec): Add pthread_attr_getstackaddr.
(std-notimpl): Remove pthread_attr_[gs]etstackaddr, as they were
removed from SUSv4.
* thread.cc (pthread_attr::pthread_attr): Initialize stackaddr.
(pthread_attr_getstack): New function.
(pthread_attr_getstackaddr): New function.
(pthread_attr_setstacksize): Return EINVAL if passed size less than
PTHREAD_STACK_MIN, as required by POSIX.
(pthread_getattr_np): New function.
* thread.h (class pthread_attr): Add stackaddr member.
* include/pthread.h (pthread_attr_getstack): Declare.
(pthread_attr_getstackaddr): Declare unconditionally.
(pthread_attr_setstack): Declare inside false conditional for reference.
(pthread_getattr_np): Declare.
* include/cygwin/version.h (CYGWIN_VERSION_API_MINOR): Bump.