GPU: Updated g_last_ticks variable to be more descriptive (represents CPU tick count of last vertical line).

GSP: Cleaned up code and added additional comments.

GSP: Removed unnecessary TODO comment.

GSP: Changed u32 iterators in TriggerCmdReqQueue to unsigned.

- Various other cleanups.

Core: Added a comment to explain the logic for the RunLoop iterations.

- Unused code
- Was not correct for unaligned memory reads

MemMap: Cleaned up Read32 unaligned memory access.

Templates shouldn't be marked as inline if they aren't defined in the header.

Also makes the illogical component order more obvious.

Anonymous structs are not standard C++, hence don't use them.