ndisasm: factor out the common operand-extraction code
ndisasm: factor out the common operand-extraction code

Factor out the common operand-extraction code in the disassembler, as
previously done in the assembler.

projedi/nasm,letolabs/nasm,turingstudio/nasm,Distrotech/nasm,turingstudio/nasm,letolabs/nasm,letolabs/nasm,techkey/nasm,turingstudio/nasm,Distrotech/nasm,techkey/nasm,projedi/nasm,Distrotech/nasm,projedi/nasm,projedi/nasm,projedi/nasm,techkey/nasm,techkey/nasm,turingstudio/nasm,Distrotech/nasm,techkey/nasm