Fix configure

Author: encukou

configure

@@ -5493,7 +5493,7 @@ fi
 AC_CHECK_FUNCS([ \
   accept4 alarm bind_textdomain_codeset chmod chown clearenv \
   clock closefrom close_range confstr \
-  copy_file_range ctermid dladdr dup execv explicit_bzero explicit_memset \
+  copy_file_range ctermid dladdr dup dup3 execv explicit_bzero explicit_memset \
   faccessat fchmod fchmodat fchown fchownat fdopendir fdwalk fexecve \
   fork fork1 fpathconf fstatat ftime ftruncate futimens futimes futimesat \
   gai_strerror getegid geteuid getgid getgrent getgrgid getgrgid_r \
@@ -5502,7 +5502,7 @@ AC_CHECK_FUNCS([ \
   getpwent getpwnam_r getpwuid getpwuid_r getresgid getresuid getrusage getsid getspent \
   getspnam getuid getwd grantpt if_nameindex initgroups kill killpg lchown linkat \
   lockf lstat lutimes madvise mbrtowc memrchr mkdirat mkfifo mkfifoat \
-  mknod mknodat mktime mmap mremap nice openat opendir pathconf pause pipe \
+  mknod mknodat mktime mmap mremap nice openat opendir pathconf pause pipe pipe2 \
   plock poll ppoll posix_fadvise posix_fallocate posix_openpt posix_spawn posix_spawnp \
   posix_spawn_file_actions_addclosefrom_np \
   pread preadv preadv2 process_vm_readv \