ref: 3d71446ecb6569add0d9eaf2e7e4a05d99bd2625 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) ;;