DownloadStream corrupts data on large reader inputs

[soypat]

Not sure what is causing it but for large files i.e. ~15MB the data is read correctly by the Go stack but then is corrupted somewhere along the way of the javascript stack from what I can tell, starting here: https://github.com/soypat/gwasm/blob/main/gwasm.go#L55. Maybe worth finding a better method