Expose B460800 & B921600 on netbsd

Author: Susurrus

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

@@ -641,6 +641,9 @@ pub const P_ALL: idtype_t = 0;
 pub const P_PID: idtype_t = 1;
 pub const P_PGID: idtype_t = 4;
 
+pub const B460800: ::speed_t = 460800;
+pub const B921600: ::speed_t = 921600;
+
 extern {
     pub fn aio_read(aiocbp: *mut aiocb) -> ::c_int;
     pub fn aio_write(aiocbp: *mut aiocb) -> ::c_int;