fix: read stream signature

[willemneal]

It is compared to a usize later and used as one later.

• I've read the contributing guidelines

[willemneal]

@dcodeIO I reverted back to isize and adding casting to the comparison. I added a line to the wasi tests, but locally it reported that it was skipped due to big int integration. Is there a way to not skip the test? Is it still compiled when skipped?

[dcodeIO]

The mechanism to enable certain features in the test suite is setting the ASC_FEATURES environment variable. One can set it to a comma separated list of features (see tests/features.json), or just * to enable all features. CI runs a subset of them in the "Features" job. If a feature is not enabled, affected tests are skipped fully, including when compiling to/updating fixtures.

[willemneal]

@dcodeIO I added std-wasi/process and std-wasi/crypto to the features CI test.

[dcodeIO]

Thank you! :)