message: impl set_flags on fd
diff: @@ -303,7 +303,15 @@ pub fn fd_fdstat_set_flags(
  flags: __wasi_fdflags_t,
  ) -> __wasi_errno_t {
  debug!("wasi::fd_fdstat_set_flags");
  - unimplemented!()
  + let state = get_wasi_state(ctx);
  + let fd_entry = wasi_try!(state.fs.fd_map.get_mut(&fd).ok_or(__WASI_EBADF));
  +
  + if fd_entry.rights & __WASI_RIGHT_FD_FDSTAT_SET_FLAGS == 0 {
  + return __WASI_EACCES;
  + }
  +
  + fd_entry.flags = flags;
  + __WASI_ESUCCESS
  }
  /// ### `fd_fdstat_set_rights()`
  