* cygthread.cc (cygthread::stub): Revert previous change and again subsume

cygthread::stub2.  Just return from function now since ExitThread is guaranteed
by automatic _threadinfo wrapper.  Define as per ThreadProc convention.
(cygthread::stub2): Remove.
(cygthread::simplestub): Perform similar operations to cygthread::stub.
(cygthread::simplestub2): Remove.
* cygthread.h (cygthread::stub): Declare as per ThreadProc convention.
(cygthread::stub2): Remove declaration.
(cygthread::simplestub): Declare as per ThreadProc convention.
(cygthread::simplestub2): Remove declaration.
* cygtls.h (_threadinfo::call): Define first argument as per ThreadProc
convention.
(_threadinfo::call2): Ditto.
(_tlsbase): Define as char * pointer.
(_tlstop): New definition.
(_main_tls): Define here.
* dcrt0.cc (alloc_stack): Revert previous change which called init_thread since
information would be overwritten by fork later anyway.
(dll_crt0_1): Use _tlsbase and _tlstop for setting stack bottom, top.
* exceptions.cc: Move _main_tls declaration to cygtls.h.
(_threadinfo::call): Define first argument as per ThreadProc convention.
(_threadinfo::call2): Call ExitThread with thread function return value.
(_threadinfo::init_thread): Don't initialize cygtls to zero if input arg is
NULL.
* fork.cc (fork_child): Reset _main_tls here.  Reinitialize parts of _my_tls
after copying data from parent.
* init.cc (threadfunc_fe): New function.  Front-end for all threads created in
cygwin processes.
(munge_threadfunc): New function.
(dll_entry): Call munge_threadfunc to force the call of a thread wrapper.
* thread.cc (pthread::thread_init_wrapper): Perform similar operations to
cygthread::stub.
(pthread::thread_init_wrapper2): Remove.
* thread.h (pthread::thread_init_wrapper): Declare as per ThreadProc
convention.
(pthread::thread_init_wrapper2): Remove declaration.
* window.cc (Winmain): Just return from function now since ExitThread is
guaranteed by automatic _threadinfo wrapper.

winsup/cygwin/thread.h

@@ -502,8 +502,7 @@ public:
   virtual void pop_cleanup_handler (int const execute);
 
   static pthread* self ();
-  static void thread_init_wrapper (void *);
-  static void thread_init_wrapper2 (void *, void *);
+  static DWORD WINAPI thread_init_wrapper (void *);
 
   virtual unsigned long getsequence_np();