Set that same options on the objc-static target as the objc target

[madsmtm]

I still can't get static linking to work, but this makes it slightly better

[davidchisnall]

Thanks. I'd like to get static linking working, but it hasn't been a priority for me (and I'd really like to add static linking to CI tests to make sure it really works).

The CMake is very old (2.x-era stuff) and doesn't look very much like modern CMake. In particular, modern CMake officially supports Objective-C, so we could remove a lot of hacks. I'd be very happy to take patches to clean it up!

The CI failures on Ubuntu look new, can you take a look at them?

[madsmtm]

Can't immediately see why the build failure should be because of this PR.

Anyhow, not very experienced in CMake (primarily Rust background), but I might find the time to tinker with it - no promises though!

[davidchisnall]

From the error, it look as if libunwind is being added on static builds now, but that functionality should come from something with a different name on static builds? Or maybe Ubuntu 18.04's clang just doesn't ship a static libunwind?