message: Handle zero-size mmap in target = windows as we do for target != windows.
  Remove dbg!() statements.
diff: @@ -132,6 +132,12 @@ impl Mmap {
  assert_eq!(mapping_size & (page_size - 1), 0);
  assert_eq!(accessible_size & (page_size - 1), 0);
  + // VirtualAlloc may return ERROR_INVALID_PARAMETER if the size is zero,
  + // so just special-case that.
  + if mapping_size == 0 {
  + return Ok(Self::new());
  + }
  +
  Ok(if accessible_size == mapping_size {
  // Allocate a single read-write region at once.
  let ptr = unsafe {
  @@ -143,7 +149,6 @@ impl Mmap {
  )
  };
  if ptr.is_null() {
  - dbg!(mapping_size);
  return Err(io::Error::last_os_error().to_string());
  }
  @@ -156,7 +161,6 @@ impl Mmap {
  let ptr =
  unsafe { VirtualAlloc(ptr::null_mut(), mapping_size, MEM_RESERVE, PAGE_NOACCESS) };
  if ptr.is_null() {
  - dbg!(mapping_size);
  return Err(io::Error::last_os_error().to_string());
  }
  