Test failures on 32-bit arches

[werdahias]

Hi, recently I got async-zip uploaded to debian. The testsuite fails on 32-bit arches:

warning: function `compress_to_mem` is never used
  --> tests/common/mod.rs:22:14
    |
    | pub async fn compress_to_mem(compress: Compression) -> Vec<u8> {
    |              ^^^^^^^^^^^^^^^

 error[E0080]: evaluation of constant value failed
  --> src/tests/write/zip64/mod.rs:17:34
   |
   | const BATCHED_FILE_SIZE: usize = NUM_BATCHES * BATCH_SIZE;
   |                                  ^^^^^^^^^^^^^^^^^^^^^^^^ attempt to compute `42950_usize * 100000_usize`, which would overflow

 For more information about this error, try `rustc --explain E0080`.
 error: could not compile `async_zip` due to previous error

[Majored]

Do you happen to know if this is a regression or is this the first version you've tested on?

[werdahias]

This is just the first version I tested