lock: correctly initialise semaphore on Windows

Ensure that we create the semaphore on Windows otherwise we do not get a
valid lock.

Author: compnerd

src/shims/lock.h

@@ -285,6 +285,9 @@ _dispatch_thread_event_init(dispatch_thread_event_t dte)
 	dte->dte_value = 0;
 #else
 	_dispatch_sema4_init(&dte->dte_sema, _DSEMA4_POLICY_FIFO);
+#if defined(_WIN32)
+	_dispatch_sema4_create(&dte->dte_sema, _DSEMA4_POLICY_FIFO);
+#endif
 #endif
 }