* cygwin.din (pthread_attr_getguardsize): Export.
(pthread_attr_setguardsize): Export.
(pthread_attr_setstack): Export.
(pthread_attr_setstackaddr): Export.
* init.cc (dll_entry): Remove wow64_test_stack_marker. Check for
unusual stack address by testing stack addresses from current TEB.
Check validity of _my_tls by testing if it's within the stack as
given in current TEB.
* miscfuncs.cc (struct thread_wrapper_arg): New structure used to
push all required information to thread_wrapper function.
(thread_wrapper): Wrapper function for actual thread function.
If an application stack has been given, change %ebp and %esp so that
the thread function runs on that stack. If the thread has been created
by CygwinCreateThread, set up the POSIX guard pages if necessary.
(CygwinCreateThread): New function.
* miscfuncs.h (CygwinCreateThread): Declare.
* ntdll.h (struct _TEB): Define all members up to Peb.
* posix.sgml (std-susv4): Move pthread_attr_getguardsize,
pthread_attr_setguardsize and pthread_attr_setstack here.
(std-deprec): Add pthread_attr_setstackaddr.
* sysconf.cc (sca): Set _SC_THREAD_ATTR_STACKADDR to
_POSIX_THREAD_ATTR_STACKADDR.
* thread.cc (pthread::precreate): Copy pthread_attr stackaddr and
guardsize members.
(pthread::create): Call CygwinCreateThread.
(pthread_attr::pthread_attr): Initialize guardsize.
(pthread_attr_setstack): New function.
(pthread_attr_setstackaddr): New function.
(pthread_attr_setguardsize): New function.
(pthread_attr_getguardsize): New function.
(pthread_getattr_np): Copy attr.guardsize.
* thread.h (pthread_attr): Add member guardsize.
* include/pthread.h (pthread_attr_getguardsize): Declare.
(pthread_attr_setguardsize): Declare.
* include/cygwin/version.h: Bump API minor number.