Go 1.20 introduced automatic seeding of the
[`math/rand`](/pkg/math/rand) global random number generator,
controlled by the [`randautoseed` setting](/pkg/math/rand/#Seed).

Go 1.20 introduced the concept of fallback roots for use during certificate verification,
controlled by the [`x509usefallbackroots` setting](/pkg/crypto/x509/#SetFallbackRoots).

Go 1.20 removed the preinstalled `.a` files for the standard library

	switch obj := obj.(type) {
	case *types.Const:
		if w.isDeprecated(obj) {
			w.emitf("const %s //deprecated", obj.Name())
		}
		w.emitf("const %s %s", obj.Name(), w.typeString(obj.Type()))
		x := obj.Val()
		short := x.String()
		exact := x.ExactString()
		if short == exact {
			w.emitf("const %s = %s", obj.Name(), short)
		} else {
			w.emitf("const %s = %s  // %s", obj.Name(), short, exact)
		}

	if err := writeHeader(w.cw, h); err != nil {
		return nil, err
	}
	// If we're creating a directory, fw is nil.
	w.last = fw
	return ow, nil
}

func writeHeader(w io.Writer, h *header) error {
	const maxUint16 = 1<<16 - 1
	if len(h.Name) > maxUint16 {
		return errLongName
	}
	if len(h.Extra) > maxUint16 {
		return errLongExtra
	}

	var buf [fileHeaderLen]byte
	b := writeBuf(buf[:])