Some special IP addresses are being wrongly detected as globally routable

[achanda]

An example is the special broadcast address 255.255.255.255/32 which is being detected as globally routable

Abhishek@Abhisheks-MacBook-Pro:~/src/rust (master %=)$ cat ip-test.rs
#![feature(ip)]
use std::net::Ipv4Addr;

fn main() {
    let x = Ipv4Addr::new(255,255,255,255);
    println!("{0}", x.is_global())
}
Abhishek@Abhisheks-MacBook-Pro:~/src/rust (master %=)$ ./ip-test
true
Abhishek@Abhisheks-MacBook-Pro:~/src/rust (master %=)$ ./x86_64-apple-darwin/stage2/bin/rustc --version --verbose
rustc 1.0.0-dev (c897ac04e 2015-04-10) (built 2015-04-10)
binary: rustc
commit-hash: c897ac04e2ebda378fd9e38f6ec0878ae3a2baf7
commit-date: 2015-04-10
build-date: 2015-04-10
host: x86_64-apple-darwin
release: 1.0.0-dev

This is because the code [1] does not take into account these special class of address as defined by RFC 6890 [2].

[1] https://doc.rust-lang.org/src/std/net/ip.rs.html#119
[2] http://tools.ietf.org/html/rfc6890

[achanda]

I'd be happy to fix this.