Trace memory read in simulator for amo

[ghost]

simulator-riscv64.h:437:

  template <typename T, typename OP>
  T amo(int64_t addr, OP f, Instruction* instr, TraceType t) {
    auto lhs = ReadMem<T>(addr, instr);
    // TODO(RISCV): trace memory read for AMO
    WriteMem<T>(addr, (T)f(lhs), instr);
    return lhs;
  }

[lazyparser]

@qjivy please find out whether this issue is still relevant or not.