Fixed issues where WaitForMultipleObjects may hang when given a NULL process. Caused by incorrect placement into an array of valid processes.

src/uniproc_win64.c

@@ -155,8 +155,7 @@ void uniproc_await_processes(const uniproc_process* p, int* return_codes, const
 	for (size_t i = 0; i < num_processes; ++i)
 	{
 		if (uniproc_is_process_null(p + i)) continue;
-		h[i] = (HANDLE)p[i]._proc_hdl;
-		num_valid_handles++;
+		h[num_valid_handles++] = (HANDLE)p[i]._proc_hdl;
 	}
 	if (num_valid_handles == 0) return;
 	WaitForMultipleObjects(num_valid_handles, h, 1, INFINITE);