ref: 714a85cedc8eea6c4c4d95c074160e0a2ca9e477 dir: /lib/std/sjlj.myr/
pkg std = type jmpbuf = struct regs : uint64[8] ;; extern const setjmp : (jb : jmpbuf# -> bool) extern const longjmp : (jb : jmpbuf# -> void) ;;