Properly Handle BPF_PSEUDO_CALL instructions

[zandi]

This was first seen in a Solana Hello World program https://github.com/solana-labs/example-helloworld

It looks like the BPF_PSUEDO_CALL variant is a pc-relative call. We disassemble it correctly, but probably need to add something to the emulation step to recognize the fact that it's calling into other bpf instructions (and the target site is a function), rather than calling into a bpf helper (which is currently our assumption of all call instructions).

https://elixir.bootlin.com/linux/v5.19-rc2/source/kernel/bpf/disasm.c#L267