memory() is only implemented for Linux and Windows
Show warning/error and skip test

Index: scripts/miscellaneous/memory.m
--- scripts/miscellaneous/memory.m.orig
+++ scripts/miscellaneous/memory.m
@@ -151,7 +151,7 @@
 
 function [userdata, systemdata] = memory ()
 
-  if ((! isunix () || ismac ()) && ! ispc ())
+  if (1)
     if (nargout > 0)
       error ("memory: function not yet implemented for this architecture");
     else
@@ -280,14 +280,14 @@ function [status, meminfo] = lmemory ()
 endfunction
 
 
-%!testif ; (isunix () && ! ismac ()) || ispc ()
+%!testif ; (0)
 %! [user, syst] = memory ();
 %! assert (user.mem_used_octave > 0);
 %! assert (user.ram_used_octave <= user.mem_used_octave);
 %! assert (user.mem_used_octave < syst.SystemMemory.Total);
 %! assert (user.MemAvailableAllArrays <= syst.SystemMemory.Available);
 
-%!testif ; (! isunix () || ismac ()) && ! ispc ()
+%!testif ; (1)
 %! fail ("[user] = memory ()",
 %!       "function not yet implemented for this architecture");
 %! fail ("memory ()", "warning",