some refactoring
- reordered instructions
- added function list
implemented the VM side of "this" (property method calls)
- updated various function structures to include the parameter
- updated vm_call to handle the existence of first "this" in argument list
- updated SI_CALL to include a way to pass the existence of "this"
fixed a major register allocation bug, implemented 'this'
- fixed a register allocation bug where registers would overwrite arguments
- made an argument overwrite test
- implemented method calls and definitions
- implemented sgs_Method: it unlocks 'this' as the first argument
- made 1 success test and two failure tests
p.s. improved performance by fixing the argument overwrite bug..