👷 Add tests for unwind_frame

[kammce]

unwind_frame should be reasonably easy to test with. You pass it a set of instructions and a cpu state and it should just work. You can create your own stack memory by creating an std::array<uint32_t, N>, filling it with the necessary information you'd see from a typical function call and assign the last position of the stack as the stack pointer. Then the CPU state can be checked against what the expected CPU state should be after the unwind has taken place.

Might even be helpful to have a class manage generating the stack memory. Something like this perhaps?

template <size_t Length>
class arm_abi_stack {

  void push(std::uint32_t lr, ...);
  // etc

  std::array<std::uint32_t, Length> stack{};
  std::uint32_t* stack_pointer = stack.data();
};