AArch64 st2 instruction missing offset operand

[adamjseitz]

cstool -d arm64 '40809f4c'
 0  40 80 9f 4c  st2    {v0.16b, v1.16b}, [x2], #32
        ID: 710 (st2)
        op_count: 3
                operands[0].type: REG = v0
                operands[0].access: READ
                        Vector Arrangement Specifier: 0x1
                operands[1].type: REG = v1
                operands[1].access: READ | WRITE
                        Vector Arrangement Specifier: 0x1
                operands[2].type: MEM
                        operands[2].mem.base: REG = x2
                operands[2].access: READ
        Write-back: True
        Registers read: v0 v1 x2
        Registers modified: v1 x2
        Groups: neon

The offset, #32, is printed as part of the instruction string, but not present in the operands array. This makes the instruction indistinguishable from the no-offset variant, st2 {v0.16b, v1.16b}, [x2].