ref: 1ed7430691158c6a2a0c5a7bae36e9e49a43a0e2 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) ;;