489   struct MachOSegmentCommand {  struct in v8::internal::GDBJITInterface::MachO
490     uint32_t cmd;
491     uint32_t cmdsize;
492     char segname[16];
494     uint32_t vmaddr;
495     uint32_t vmsize;
496     uint32_t fileoff;
497     uint32_t filesize;
499     uint64_t vmaddr;
500     uint64_t vmsize;
501     uint64_t fileoff;
502     uint64_t filesize;
504     uint32_t maxprot;
505     uint32_t initprot;
506     uint32_t nsects;
507     uint32_t flags;