TODO

- Add an origin-follow command which will continuously do an origin until it gets to a place
  where it can't go any further. Would this be useful on a heap allocated addres?
  It would take us into the malloc implementation, when we probably want to stop
  at the allocation site. Perhaps we could special case malloc somehow...
- Add an origin-revert command that takes you back to the place where you started the last
  origin-follow. It should be possible to implement this using gdb's checkpoint support.
- Switch to capstone 4. This will allow us to directly determine which registers are
  being read and written, which should improve the reliablity
- Add the ability to choose which operand to follow when there's more than one possible source.
- Tighten up operand size and offset handling. This will allow for more precise watching
  of sizes other than int.
- Port to C++ and include directly in RR. This should improve performance and should
  fix the missed write watchpoints for unchanged values problem.
- Disambiguate sources depending on their value. i.e. if you have something like a = a + b where
  b = 0.