Porting the Go compiler to Go

Go is inherently a cross-compiler. Every build is a cross-compile. You set an couple of environment variables to adjust the build target, and if the standard library has been installed as a privileged user, you'll need to make sure that's redone as a privileged user (or say "screw it" and run with a user install of Go).

Go's is the cleanest cross-compilation experience I've ever had, and the nearest competition is NetBSD's setup.