Part 8: Code cache and native block tag changes.

* Turn the 5 translation caches into a read-only area cache (ROM/BIOS) and a writable area cache (IWRAM/EWRAM/VRAM).
* Turn metadata clearing into its own procedure.
* Reuse native code blocks based on the GBA code. That is, if the game places the same code back into IWRAM/EWRAM/VRAM, it looks that up and points to the already-compiled code.
* (Tuning) Set some initial sizes for the two caches.
* (DSTwo-specific) Add statistics for reused and recompiled opcodes. These are performance-impacting, so #define PERFORMANCE_IMPACTING_STATISTICS to get them.
* (DSTwo-specific) Reduce the number of rewinds to 2. This is likely temporary, and is just there to make sure I don't cause memory overflows.