Several issues:
1. Several terminal instructions did not stop at the end of a single-step block
2. x64 backend for the A32 frontend sometimes polluted upper_location_descriptor with the single-stepping flag
We also introduce the enable_optimizations parameter to the A32 frontend.
Removes unnecessary header dependencies that have accumulated over time
as changes have been made. Lessens the amount of files that need to be
rebuilt when the headers change.
The AddressRange structure isn't used anywhere within the codebase, so
this can be removed. Particularly because there's no real appeal/heavy
potential use of it in the future that isn't trivial to add back if
needed.