Add new x86 instruction groups

- VM: Virtual Machine
- INT: Interrupts
- IRET: Interupt returns
- CALL: Subroutine call
- RET: Subroutine return

Includes a special case for writes to port 0xb2, which triggers an SMI
x86 instruction groups: Fix RET/IRET mapping.
Merge branch 'feature/x86-groups' of https://github.com/parasyte/capstone into test