Auto merge of #621 - mneumann:dragonfly-at-fixes, r=alexcrichton

Fix AT_ constants for DragonFly

Author: bors

src/unix/bsd/freebsdlike/dragonfly/mod.rs

@@ -404,6 +404,13 @@ pub const TIOCMODG: ::c_uint = 0x40047403;
 pub const TIOCMODS: ::c_ulong = 0x80047404;
 pub const TIOCREMOTE: ::c_ulong = 0x80047469;
 
+// Constants used by "at" family of system calls.
+pub const AT_FDCWD:            ::c_int = 0xFFFAFDCD; // invalid file descriptor
+pub const AT_SYMLINK_NOFOLLOW: ::c_int = 1;
+pub const AT_REMOVEDIR:        ::c_int = 2;
+pub const AT_EACCESS:          ::c_int = 4;
+pub const AT_SYMLINK_FOLLOW:   ::c_int = 8;
+
 extern {
     pub fn mprotect(addr: *mut ::c_void, len: ::size_t, prot: ::c_int)
                     -> ::c_int;

src/unix/bsd/freebsdlike/freebsd/mod.rs

@@ -508,6 +508,12 @@ pub const P_ALL: idtype_t = 7;
 pub const B460800: ::speed_t = 460800;
 pub const B921600: ::speed_t = 921600;
 
+pub const AT_FDCWD: ::c_int = -100;
+pub const AT_EACCESS: ::c_int = 0x100;
+pub const AT_SYMLINK_NOFOLLOW: ::c_int = 0x200;
+pub const AT_SYMLINK_FOLLOW: ::c_int = 0x400;
+pub const AT_REMOVEDIR: ::c_int = 0x800;
+
 extern {
     pub fn __error() -> *mut ::c_int;
 

src/unix/bsd/freebsdlike/mod.rs

@@ -452,11 +452,6 @@ pub const F_SETFD: ::c_int = 2;
 pub const F_GETFL: ::c_int = 3;
 pub const F_SETFL: ::c_int = 4;
 
-pub const AT_EACCESS: ::c_int = 0x100;
-pub const AT_SYMLINK_NOFOLLOW: ::c_int = 0x200;
-pub const AT_SYMLINK_FOLLOW: ::c_int = 0x400;
-pub const AT_REMOVEDIR: ::c_int = 0x800;
-
 pub const SIGTRAP: ::c_int = 5;
 
 pub const GLOB_APPEND  : ::c_int = 0x0001;
@@ -876,8 +871,6 @@ pub const SEM_FAILED: *mut sem_t = 0 as *mut sem_t;
 
 pub const CRTSCTS: ::tcflag_t = 0x00030000;
 
-pub const AT_FDCWD: ::c_int = -100;
-
 f! {
     pub fn WIFCONTINUED(status: ::c_int) -> bool {
         status == 0x13