[PATCH v3] Mark win32's pthread_exit() as NORETURN

The pthread_exit() function is not expected to return. Ever. On Windows, we call ExitThread() whose documentation claims: "Ends the calling thread", i.e. there is no condition in which this function simply returns: https://msdn.microsoft.com/en-us/library/windows/desktop/ms682659

While at it, fix the return type to be void, as per http://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_exit.html

Pointed out by Jeff King, helped by Stefan Naewe, Junio Hamano & Johannes Sixt.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 compat/win32/pthread.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
Interdiff vs v2:

 diff --git a/compat/win32/pthread.h b/compat/win32/pthread.h
 index 148db60..b6ed9e7 100644
 --- a/compat/win32/pthread.h
 +++ b/compat/win32/pthread.h
 @@ -78,7 +78,7 @@ extern int win32_pthread_join(pthread_t *thread, void **value_ptr);
  #define pthread_equal(t1, t2) ((t1).tid == (t2).tid)
  extern pthread_t pthread_self(void);
  
 -static inline int NORETURN pthread_exit(void *ret)
 +static inline void NORETURN pthread_exit(void *ret)
  {
  	ExitThread((DWORD)(intptr_t)ret);
  }