Add FreeBSD get[pw|gr]ent_r, forgotten in rust-lang#934

Sorry, accidentally forgot this when submitting rust-lang#934..

Author: ctrlcctrlv

Cargo.lock

@@ -1,7 +1,7 @@
 [package]
 
 name = "libc"
-version = "0.2.38"
+version = "0.2.39"
 authors = ["The Rust Project Developers"]
 license = "MIT/Apache-2.0"
 readme = "README.md"

Cargo.toml

@@ -1004,6 +1004,15 @@ extern {
                         groups: *mut ::gid_t,
                         ngroups: *mut ::c_int) -> ::c_int;
     pub fn initgroups(name: *const ::c_char, basegid: ::gid_t) -> ::c_int;
+    #[cfg_attr(target_os = "netbsd", link_name = "__getpwent_r50")]
+    pub fn getpwent_r(pwd: *mut ::passwd,
+                      buf: *mut ::c_char,
+                      buflen: ::size_t,
+                      result: *mut *mut ::passwd) -> ::c_int;
+    pub fn getgrent_r(grp: *mut ::group,
+                      buf: *mut ::c_char,
+                      buflen: ::size_t,
+                      result: *mut *mut ::group) -> ::c_int;
     pub fn mq_open(name: *const ::c_char, oflag: ::c_int, ...) -> ::mqd_t;
     pub fn mq_close(mqd: ::mqd_t) -> ::c_int;
     pub fn mq_getattr(mqd: ::mqd_t, attr: *mut ::mq_attr) -> ::c_int;