Change type of public/native indices from 'int' to 'cell'
Replace C-style function pointer casts with asmjit_cast<>
AsmJit: Fix redefinition of fixed-size int types in VS 2008

Both amx.h and AsmJit define their own (u)int(8|16|32|64)_t in global
namespace so I've put the AsmJit ones in namespace AsmJit.
Fix function prototypes in comments
Fix indirect jumps
Fix lctrl/sctrl still accessing AMX directly
Add TODO.txt