byteArray: Fix bug with length > maxint32
byteArray: Fix bug with length > maxint32

This is extremely unlikely to happen, but I noticed it while making some
other changes.

https://bugzilla.gnome.org/show_bug.cgi?id=742249

endlessm/gjs,endlessm/gjs,endlessm/gjs,endlessm/gjs,endlessm/gjs