How can I set up a http2 server in Go 1.8 without third party libraries?

I heard that http2 would be supported in the latest Go versions. How can I put up a http2 server without using golang.org/x/net/http2?

In previous versions you could do something like this:

package main
import (
    "log"
    "net/http"
    "os"
    "golang.org/x/net/http2"
)
func main() {
    cwd, err := os.Getwd()
    if err != nil {
        log.Fatal(err)
    }
    srv := &http.Server{
        Addr:    ":443",
        Handler: http.FileServer(http.Dir(cwd)),
    }
    http2.ConfigureServer(srv, &http2.Server{})
    log.Fatal(srv.ListenAndServeTLS("server.crt", "server.key"))
}

You just use net/http in most instances:

> Starting with Go 1.6, the http package has transparent support for the HTTP/2 protocol when using HTTPS.
>
> The http package's Transport and Server both automatically enable HTTP/2 support for simple configurations. To enable HTTP/2 for more complex configurations, to use lower-level HTTP/2 features, or to use a newer version of Go's http2 package, import "golang.org/x/net/http2" directly and use its ConfigureTransport and/or ConfigureServer functions. Manually configuring HTTP/2 via the golang.org/x/net/http2 package takes precedence over the net/http package's built-in HTTP/2 support.