ref: 6c0e6856de4a72b7d6ab99a184d213b18a3dea14 dir: /lib/std/sjlj+x64.myr/
pkg std = type jmpbuf = struct regs : uint64[9] ;; extern const setjmp : (jb : jmpbuf# -> bool) extern const longjmp : (jb : jmpbuf# -> void) ;;