< Memory barrier operation (ISB/DMB/DSB instructions).
< floating point value for FP operand
< immediate value, or index for C-IMM or IMM operand
< base/index/scale/disp value for MEM operand
< PRFM operation.
< PState field of MSR instruction.
< register value for REG operand
< IC/DC/AT/TLBI operation (see arm64_ic_op, arm64_dc_op, arm64_at_op, arm64_tlbi_op)