Skeletons: Improve support for 32-bit architectures

[qmonnet]

If a bpf program has a global variable of type: long, its skeleton will include a bss map that will have a field for this variable. The long variable in BPF is 64-bit. if we are working on a 32-bit machine, the generated skeleton has to compile for that machine where long is 32-bit.

More context: https://lore.kernel.org/bpf/CANk7y0joRFw2F4iAuN9r-dWWMvOmbFZz_J4rhGhgVFjdnxPTYw@mail.gmail.com/