Do not hold GC_fault_handler_lock when in Sleep (Win32)

Do not hold GC_fault_handler_lock when in Sleep (Win32)
(fix of commits 0c0e4cd0b, 449eda034)

Also, reduce a period between GetExitCodeThread and SuspendThread.

* win32_threads.c [DEBUG_THREADS] (GC_suspend): Call GC_log_printf()
before UNPROTECT_THREAD().
* win32_threads.c [DEBUG_THREADS && !MSWINCE] (GC_suspend): Call
GC_acquire_dirty_lock() before GetExitCodeThread(); call
GC_release_dirty_lock() immediately if GetExitCodeThread() failed.
* win32_threads.c [MSWINCE || RETRY_GET_THREAD_CONTEXT] (GC_suspend):
Wrap Sleep() call with GC_release/acquire_dirty_lock().