Swift v5.7 - partially complete

I will not attach binary here, because there is some problems with it - most important you can't run it on macOS 13, because latest version was built with macOS 14. Here is issue connected to it. May be later this changes can be applied to produce release toolchain.

This tag should be buildable on macOS 13 and 14, if you use brew to install libxml2 and autoconf ($ brew install libxml2 and $ brew install autoconf automake libtool)