The Go language is gaining popularity, so we will reach a point where tools and libraries we want to use will be written in Go. As such, we need a Go compiler in our build system.
Just adding "go" to "--enable-languages" seems to mostly work. The bootstrap compiler builds just fine with go support, but the final compiler fails with some odd "-Werror=cast-qual" bug building the go runtime. It should hopefully be easily fixed.
Note that we get a rather old Go version, though, as we have a rather old gcc. It might not be sufficient for what we need and need to upgrade gcc as well.