Revert the reversion and go with implementation described in cgf-000017, with

some modifications.
* init.cc (dll_entry): Revert previous change.
* miscfuncs.cc: Include sigproc.h for exit_thread declaration.
* winsup.h (ExitThread): Define as 'exit_thread' to ensure no accidental use.
* sigproc.cc (exit_thread): New function.
(wait_sig): Handle __SIGTHREADEXIT case.  Don't just block rather than
returning from this function.
* sigproc.h (__SIGTHREADEXIT): New enum.
(exit_thread): Declare.
* sync.cc (muto::release): Accept a tls command-line argument.
* sync.h (muto::release): Accept a tls command-line parameter.  Default to
&_my_tls.
* cygerrno.h (__set_errno): Define as extern so that no function code is ever
emitted.
* cygserver_ipc.h (cygserver_ipc.h): Ditto.
* miscfuncs.h (transform_chars): Ditto.
* path.h (has_attribute): Ditto.
* security.h (privilege_luid): Ditto.
* winsup.h (flush_file_buffers): Ditto.

winsup/cygwin/sync.cc

@@ -4,7 +4,8 @@
    which is intended to operate similarly to a mutex but attempts to
    avoid making expensive calls to the kernel.
 
-   Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009, 2010 Red Hat, Inc.
+   Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009, 2010, 2011, 2012
+   Red Hat, Inc.
 
 This file is part of Cygwin.
 
@@ -109,10 +110,8 @@ muto::acquired ()
 
 /* Return the muto lock.  Needs to be called once per every acquire. */
 int
-muto::release ()
+muto::release (_cygtls *this_tls)
 {
-  void *this_tls = &_my_tls;
-
   if (tls != this_tls || !visits)
     {
       SetLastError (ERROR_NOT_OWNER);	/* Didn't have the lock. */