Add qemu runtime defs for aarch64

[twizmwazin]

This fixes the "bindings generation" reported in #2128. It is a shot in the dark: this is enough to make it compile (or reach the other error in that issue), but I don't know for sure it is correct nor do I know how to properly test it. I would advise someone to test this, or at least someone more familiar with the code and calling conventions should review it before assuming it is correct.

This file also caused libafl_qemu_stub_bindings.rs to update after rebuilding. Should I commit the changes in that file? If the file is autogenerated, should it be ignore by git altogether?

[rmalmain]

Thank you for the PR.

I'll think of a way to reduce the generations of the binding files, it is fine if you do not commit it.
i was experimenting if it was realistic always to generate them, but it seems it has slight differences depending on the compiler used, causing it to be often regenerated even when it's useless.