feat: add support for original_dst for windows

[keithmattix]

I noticed there wasn't support for original dst in Windows, so I added it. Also add windows gnu target to allow cross compiling

[Thomasdezeeuw]

It seems that at least Linux has SO_ORIGINAL_DST and IP6T_SO_ORIGINAL_DST as well, can we add it for it as well?

[keithmattix]

@Thomasdezeeuw it's already added in the sys/unix.rs file:

socket2/src/sys/unix.rs

Line 2420 in 3a93893

pub fn original_dst(&self) -> io::Result<SockAddr> {

[Thomasdezeeuw]

@Thomasdezeeuw it's already added in the sys/unix.rs file:

socket2/src/sys/unix.rs

Line 2420 in 3a93893

pub fn original_dst(&self) -> io::Result<SockAddr> {

Ah, in that case it should be moved to the src/socket.rs file to ensure the API is the same across OS.

[keithmattix]

Ok yeah I had that thought but wanted to confirm. Will make the change!