Motivation for this change

Running chromium on aarch64.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option build-use-sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS (aarch64 only)
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Fits CONTRIBUTING.md.

So far as I can tell, there's nothing about the build process for chromium that doesn't work on aarch64, except for the toolchain configuration. Removing the prefix makes it build and run.

After building this I noticed the following, which probably isn't having any effect.

      # use our own nodejs
      mkdir -p third_party/node/linux/node-linux-x64/bin
      ln -s $(which node) third_party/node/linux/node-linux-x64/bin/node

It took a number of days for this build, (admittedly with two cores idle, which is the default for this package). I don't know how viable it is to iterate on this, so I'm presenting it in its current state. Having the package build and run is better than not building at all, even if it's not perfect.