ref: 4a8bc7aa008f753c082a914a0f95ea3df09d2123 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) ;;