* child_info.h (CURR_CHILD_INFO_MAGIC): Update.

(class child_info_fork): Remove stacksize, add stackaddr and guardsize
	members.
	* dcrt0.cc (child_info_fork::alloc_stack_hard_way): Partial rewrite
	to regenerate the stack exactly as in the parent.
	(child_info_fork::alloc_stack): Set stackaddr to 0, rather than
	stacksize.
	(dll_crt0_1): Check for stackaddr before changing the stack addresses
	in the TEB.
	* fork.cc (frok::child): Check for stackaddr here.
	(frok::parent): Set ch.stackaddr and ch.guardsize if not called from
	the main thread.
	* init.cc (dll_entry): Replace pointer to NT_TIB with pointer to TEB.
	Fix incorrectly changed address test before removing _my_tls.
	Set StackLimit to NULL on Windows 2000.  Explain why.
	* miscfuncs.cc (struct thread_wrapper_arg): Store stackbase rather
	than stacksize, store commitaddr, remove guardsize.  Store all pointers
	as char * for easier address arithmetic.
	(thread_wrapper): Rewrite to remove OS stack before calling thread
	function.  Add lots of comments to explain what we do.
	(CygwinCreateThread): Reserve our own stack in case we got no
	application stack.  Add comments.
	* ntdll.h (struct _TEB): Extend defintion up to DeallocationStack
	member.
	* thread.cc (pthread_attr::pthread_attr): Use "(size_t) -1"
	rather then 0xffffffff.
	* wincap.h (wincaps::has_stack_size_param_is_a_reservation): New
	element.
	* wincap.cc: Implement above element throughout.

winsup/cygwin/wincap.cc

@@ -51,6 +51,7 @@ wincaps wincap_2000 __attribute__((section (".cygwin_dll_common"), shared)) = {
   has_fast_cwd:false,
   has_restricted_raw_disk_access:false,
   use_dont_resolve_hack:false,
+  has_stack_size_param_is_a_reservation:false,
 };
 
 wincaps wincap_2000sp4 __attribute__((section (".cygwin_dll_common"), shared)) = {
@@ -81,6 +82,7 @@ wincaps wincap_2000sp4 __attribute__((section (".cygwin_dll_common"), shared)) =
   has_fast_cwd:false,
   has_restricted_raw_disk_access:false,
   use_dont_resolve_hack:false,
+  has_stack_size_param_is_a_reservation:false,
 };
 
 wincaps wincap_xp __attribute__((section (".cygwin_dll_common"), shared)) = {
@@ -111,6 +113,7 @@ wincaps wincap_xp __attribute__((section (".cygwin_dll_common"), shared)) = {
   has_fast_cwd:false,
   has_restricted_raw_disk_access:false,
   use_dont_resolve_hack:true,
+  has_stack_size_param_is_a_reservation:true,
 };
 
 wincaps wincap_xpsp1 __attribute__((section (".cygwin_dll_common"), shared)) = {
@@ -141,6 +144,7 @@ wincaps wincap_xpsp1 __attribute__((section (".cygwin_dll_common"), shared)) = {
   has_fast_cwd:false,
   has_restricted_raw_disk_access:false,
   use_dont_resolve_hack:true,
+  has_stack_size_param_is_a_reservation:true,
 };
 
 wincaps wincap_xpsp2 __attribute__((section (".cygwin_dll_common"), shared)) = {
@@ -171,6 +175,7 @@ wincaps wincap_xpsp2 __attribute__((section (".cygwin_dll_common"), shared)) = {
   has_fast_cwd:false,
   has_restricted_raw_disk_access:false,
   use_dont_resolve_hack:true,
+  has_stack_size_param_is_a_reservation:true,
 };
 
 wincaps wincap_2003 __attribute__((section (".cygwin_dll_common"), shared)) = {
@@ -201,6 +206,7 @@ wincaps wincap_2003 __attribute__((section (".cygwin_dll_common"), shared)) = {
   has_fast_cwd:false,
   has_restricted_raw_disk_access:false,
   use_dont_resolve_hack:true,
+  has_stack_size_param_is_a_reservation:true,
 };
 
 wincaps wincap_vista __attribute__((section (".cygwin_dll_common"), shared)) = {
@@ -231,6 +237,7 @@ wincaps wincap_vista __attribute__((section (".cygwin_dll_common"), shared)) = {
   has_fast_cwd:true,
   has_restricted_raw_disk_access:true,
   use_dont_resolve_hack:false,
+  has_stack_size_param_is_a_reservation:true,
 };
 
 wincaps wincap_7 __attribute__((section (".cygwin_dll_common"), shared)) = {
@@ -261,6 +268,7 @@ wincaps wincap_7 __attribute__((section (".cygwin_dll_common"), shared)) = {
   has_fast_cwd:true,
   has_restricted_raw_disk_access:true,
   use_dont_resolve_hack:false,
+  has_stack_size_param_is_a_reservation:true,
 };
 
 wincapc wincap __attribute__((section (".cygwin_dll_common"), shared));