message: Simplify WasmPtr code
  `std::mem::size_of::<T>()` already accounts for end padding. The `align_of` code
  was not only a no-op, it would be incorrect if it wasn't.
  Thanks to Matt Itamenye on the wasmerians slack for pointing this out!
diff: @@ -125,7 +125,7 @@ impl<T: Copy + ValueType> WasmPtr<T, Array> {
  pub fn deref(self, memory: &Memory, index: u32, length: u32) -> Option<&[Cell<T>]> {
  // gets the size of the item in the array with padding added such that
  // for any index, we will always result an aligned memory access
  - let item_size = mem::size_of::<T>() + (mem::size_of::<T>() % mem::align_of::<T>());
  + let item_size = mem::size_of::<T>();
  let slice_full_len = index as usize + length as usize;
  let memory_size = memory.size().bytes().0;
  @@ -163,7 +163,7 @@ impl<T: Copy + ValueType> WasmPtr<T, Array> {
  ) -> Option<&mut [Cell<T>]> {
  // gets the size of the item in the array with padding added such that
  // for any index, we will always result an aligned memory access
  - let item_size = mem::size_of::<T>() + (mem::size_of::<T>() % mem::align_of::<T>());
  + let item_size = mem::size_of::<T>();
  let slice_full_len = index as usize + length as usize;
  let memory_size = memory.size().bytes().0;
  