message: Avoid double references to Memory
diff: @@ -37,7 +37,7 @@ pub fn read_region(memory: &wasmer::Memory, ptr: u32, max_length: usize) -> VmRe
  );
  }
  - match WasmPtr::<u8, Array>::new(region.offset).deref(&memory, 0, region.length) {
  + match WasmPtr::<u8, Array>::new(region.offset).deref(memory, 0, region.length) {
  Some(cells) => {
  // In case you want to do some premature optimization, this shows how to cast a `&'mut [Cell<u8>]` to `&mut [u8]`:
  // https://github.com/wasmerio/wasmer/blob/0.13.1/lib/wasi/src/syscalls/mod.rs#L79-L81
  @@ -81,7 +81,7 @@ pub fn write_region(memory: &wasmer::Memory, ptr: u32, data: &[u8]) -> VmResult<
  if data.len() > region_capacity {
  return Err(CommunicationError::region_too_small(region_capacity, data.len()).into());
  }
  - match WasmPtr::<u8, Array>::new(region.offset).deref(&memory, 0, region.capacity) {
  + match WasmPtr::<u8, Array>::new(region.offset).deref(memory, 0, region.capacity) {
  Some(cells) => {
  // In case you want to do some premature optimization, this shows how to cast a `&'mut [Cell<u8>]` to `&mut [u8]`:
  // https://github.com/wasmerio/wasmer/blob/0.13.1/lib/wasi/src/syscalls/mod.rs#L79-L81
  @@ -89,7 +89,7 @@ pub fn write_region(memory: &wasmer::Memory, ptr: u32, data: &[u8]) -> VmResult<
  cells[i].set(data[i])
  }
  region.length = data.len() as u32;
  - set_region(&memory, ptr, region)?;
  + set_region(memory, ptr, region)?;
  Ok(())
  },
  None => Err(CommunicationError::deref_err(region.offset, format!(
  