[PATCH] add attribute_hidden to __have_{sock_cloexec,pipe2,dup3

[Roland McGrath]

Looks good.  

It's unfortunate that any of those declarations appear in more than one
include/ header file.  Maybe we can just make sure that any users of
__have_sock_cloexec include <sys/socket.h>?

It would be worthwhile for someone to check include/*.h for any other
duplicate declarations.


Thanks,
Roland