discussion: Use capstone for `disasm()`

[tesuji]

• What the feature does cc #683 but for the disasm part only. If I understand correctly, one cencern raised in #683 is that the shellcraft module depends heavily on binutils. But I don't see this concern holds on disassembly part.
• Why the feature should exist disasm in case cross-binutils toolchain not installed.
• What tests should be included <I don't think I know this>

[peace-maker]

Sorry for the delay! I think supporting capstone as a fallback when the required binutils aren't available for disassembly is useful. Maybe even make it configurable on the context to force the use capstone.

I haven't used keystone a lot, so I don't know how much work it would be to get our shellcraft corpus to assemble. Does anyone have input there? What are the differences?

We can add support in small steps and think about ELF creation when we get to the point of only requiring binutils for that feature.