[RISCV] Support Sinval extension and hypervisor memory management fence instructions

    According to Privileged spec version-20211203

    Add Supervisor Memory-Management Instructions:
        - SINVAL.VMA, SFENCE.W.INVAL, SFENCE.INVAL.IR
    Add Hypervisor Memory-Management Instructions:
        - HFENCE.VVMA, HFENCE.GVMA, HINVAL.VVMA, HINVAL.GVMA

Signed-off-by: eric.tang <eric.tang@starfivetech.com>

Differential Revision: https://reviews.llvm.org/D117654