What is current state of iOS support of Rust?

There is a blog post that claims

Rust is now completely ported to iOS: all architectures for device/simulator are supported. Since green threads were removed, adding support of arm64 was actually almost straightforward.

Github also has an example iOS app (written in Swift) that calls into a cross-compiled framework (written in Rust).

Segmented stacks were abandoned, and there have been lots of 'fix iOS build' PRS: https://github.com/rust-lang/rust/search?q=ios&type=Issues&utf8=%E2%9C%93

I don't know more than that, though.