message: Fix Mmap creation on Windows
  Forgot to update field names...
diff: @@ -158,7 +158,8 @@ impl Mmap {
  Self {
  ptr: ptr as usize,
  - len: mapping_size,
  + total_size: mapping_size,
  + accessible_size,
  }
  } else {
  // Reserve the mapping size.
  @@ -170,7 +171,8 @@ impl Mmap {
  let mut result = Self {
  ptr: ptr as usize,
  - len: mapping_size,
  + total_size: mapping_size,
  + accessible_size,
  };
  if accessible_size != 0 {
  @@ -210,8 +212,8 @@ impl Mmap {
  let page_size = region::page::size();
  assert_eq!(start & (page_size - 1), 0);
  assert_eq!(len & (page_size - 1), 0);
  - assert_lt!(len, self.len);
  - assert_lt!(start, self.len - len);
  + assert_lt!(len, self.len());
  + assert_lt!(start, self.len() - len);
  // Commit the accessible size.
  let ptr = self.ptr as *const u8;
  @@ -291,7 +293,7 @@ impl Drop for Mmap {
  #[cfg(target_os = "windows")]
  fn drop(&mut self) {
  - if self.len != 0 {
  + if self.len() != 0 {
  use winapi::ctypes::c_void;
  use winapi::um::memoryapi::VirtualFree;
  use winapi::um::winnt::MEM_RELEASE;
  