Refactor gen_x86 to use an interface more like gen_arm and to remove the need for the caller to decide whether an 8-bit or 32-bit displacement is needed in the rdisp functions. Update m68k_to_x86 to use the new version of the gen_x86 functions and do some minor refactoring there in the process

#ifndef GDB_REMOTE_H_
#define GDB_REMOTE_H_
#include "blastem.h"

void gdb_remote_init(void);
m68k_context * gdb_debug_enter(m68k_context * context, uint32_t pc);

#endif //GDB_REMOTE_H_