valandil [1] filed a deletion request for n64-toolchain-git [2]: Upstream has changed compilation method. Will be best to create a new package which installs the entire toolchain specifically for use with the tools the upstream repo contains, as it is not likely to be useful to other packages.
[1] https://aur.archlinux.org/account/valandil/ [2] https://aur.archlinux.org/pkgbase/n64-toolchain-git/