Auto merge of #68191 - simlay:add-tvSO-target, r=nagisa

Added tvOS as targets

This is a first attempt of adding support tvOS as described in #48862. It's got a lot of overlap with [src/librustc_target/spec/apple_ios_base.rs](https:/rust-lang/rust/blob/31dd4f4acbcbdb02b0745d2136399ed664a28050/src/librustc_target/spec/apple_ios_base.rs).

I thought about refactoring `apple_ios_base.rs` to include this as well but that would require each of the ios and tvos targets to be of the something like the form `let base = opts(AppleOS::TV, Arch::Arm64)?;` I also did the same thing for watchOS because from what I can tell, all three targets (iOS, tvOS, and watchOS) have the same logic but have different parameters being sent to `xcrun`. Thoughts?

As far as the `data_layout` and other parameters to `Target`, I did as much research as I could but it really seems that processor in the [iPhone 11 is the same as the apple TV](https://en.wikipedia.org/wiki/Apple-designed_processors) so I didn't change any of those parameters.

I did get this to build and tested that it's actually running the the below logic (because the parameter to `xcrun` is `appletvos` not `tvos`).

I didn't manage to get it to actually compile a file with `fn main(){}` because I don't have the stdlib for `aarch64-apple-tvos` compiled it seems. Is there documentation for this?

Similar to the ending of rust-lang/rust#63467, I'm not sure what to do next.