ntdll/tests: Add pipe state tests.

include/winternl.h

@@ -737,6 +737,11 @@ typedef struct _FILE_PIPE_LOCAL_INFORMATION {
     ULONG NamedPipeEnd;
 } FILE_PIPE_LOCAL_INFORMATION, *PFILE_PIPE_LOCAL_INFORMATION;
 
+#define FILE_PIPE_DISCONNECTED_STATE        0x00000001
+#define FILE_PIPE_LISTENING_STATE           0x00000002
+#define FILE_PIPE_CONNECTED_STATE           0x00000003
+#define FILE_PIPE_CLOSING_STATE             0x00000004
+
 typedef struct _FILE_OBJECTID_INFORMATION {
     LONGLONG FileReference;
     UCHAR ObjectId[16];