OpenBSD: add sendmmsg and recvmmsg support.

close #3696

Author: devnexen

libc-test/semver/openbsd.txt

@@ -1210,6 +1210,7 @@ readlinkat
 reallocarray
 reboot
 recvmsg
+recvmmsg
 regcomp
 regerror
 regex_t

src/unix/bsd/netbsdlike/mod.rs

@@ -92,6 +92,11 @@ s! {
         pub piod_addr: *mut ::c_void,
         pub piod_len: ::size_t,
     }
+
+    pub struct mmsghdr {
+        pub msg_hdr: ::msghdr,
+        pub msg_len: ::c_uint,
+    }
 }
 
 pub const D_T_FMT: ::nl_item = 0;
@@ -858,6 +863,20 @@ extern "C" {
     pub fn dirname(path: *mut ::c_char) -> *mut ::c_char;
     pub fn basename(path: *mut ::c_char) -> *mut ::c_char;
     pub fn getentropy(buf: *mut ::c_void, buflen: ::size_t) -> ::c_int;
+
+    pub fn sendmmsg(
+        sockfd: ::c_int,
+        mmsg: *mut ::mmsghdr,
+        vlen: ::c_uint,
+        flags: ::c_int,
+    ) -> ::c_int;
+    pub fn recvmmsg(
+        sockfd: ::c_int,
+        mmsg: *mut ::mmsghdr,
+        vlen: ::c_uint,
+        flags: ::c_int,
+        timeout: *mut ::timespec,
+    ) -> ::c_int;
 }
 
 cfg_if! {

src/unix/bsd/netbsdlike/netbsd/mod.rs

@@ -401,11 +401,6 @@ s! {
         pub sdl_data: [::c_char; 12],
     }
 
-    pub struct mmsghdr {
-        pub msg_hdr: ::msghdr,
-        pub msg_len: ::c_uint,
-    }
-
     pub struct __exit_status {
         pub e_termination: u16,
         pub e_exit: u16,
@@ -2750,20 +2745,6 @@ extern "C" {
 
     pub fn kqueue1(flags: ::c_int) -> ::c_int;
 
-    pub fn sendmmsg(
-        sockfd: ::c_int,
-        msgvec: *mut ::mmsghdr,
-        vlen: ::c_uint,
-        flags: ::c_int,
-    ) -> ::c_int;
-    pub fn recvmmsg(
-        sockfd: ::c_int,
-        msgvec: *mut ::mmsghdr,
-        vlen: ::c_uint,
-        flags: ::c_int,
-        timeout: *mut ::timespec,
-    ) -> ::c_int;
-
     pub fn _lwp_self() -> lwpid_t;
     pub fn memmem(
         haystack: *const ::c_void,