Fix tests on platforms where long is 32-bit
Handle intermediate version of ghash value test
Fix test on platforms where size_t is 4 bytes
Several fixes for 32-bit and old GIR [merges '32bit-fixes']
Merge branch 'master' into support-gbytes
Make GLib::Bytes.new work with old GIR

This works around incorrect introspection data that indicates the passed-in
array has element type :pointer.
Add support for the GBytes type [merges 'support-gbytes']