Implemented NtSignalAndWaitForSingleObject.

diff --git a/server/registry.c b/server/registry.c
index 6f85f57..c7dcd73 100644
--- a/server/registry.c
+++ b/server/registry.c
@@ -138,6 +138,7 @@
     NULL,                    /* remove_queue */
     NULL,                    /* signaled */
     NULL,                    /* satisfied */
+    no_signal,               /* signal */
     no_get_fd,               /* get_fd */
     key_destroy              /* destroy */
 };