New review comment by ahesford on void-packages repository

https://github.com/void-linux/void-packages/pull/22785#discussion_r457492998

Comment:
I wouldn't go too crazy here. If you try building for archs that don't have binary packages, you are going to go crazy building a bunch of stuff just to get to the point where you can test your package. The main idea should be to prevent issues with trying to build official binary packages. If somebody wants to try building rustup for mips, let the user with the problem get involved with resolving any problems that shake out.