Todo

• Do something with NOR in simplifying an expression like !(a or b)
• Might be able to scope fixed vars by block; would need fixed to not just be a boolean but an option of a struct with the line numbers for the scope (which would need to be adjusted by the mips optimizer when lines are removed) done?
• Add some kind of constants library for both MIPS and MYPS to use (things like logic enumerations; "Horizontal: 20"). Going to need to think long and hard about how to implement logic types and other game constants here.