testsuite: Bump for unix 2.7

libraries/base/tests/T7773.hs

@@ -3,7 +3,7 @@ import System.Posix.IO
 
 main = do
   putStrLn "hello"
-  fd <- openFd "/dev/random" ReadOnly defaultFileFlags
+  fd <- openFd "/dev/random" ReadOnly Nothing defaultFileFlags
   threadWaitRead fd
   putStrLn "goodbye"