Fixes for setup script

setup.sh

 #!/bin/bash
-
 set -e
 
+echo "Downloading latest libc-artifacts"
+git submodule update --init --remote libc-artifacts
+
 echo "Defaulting to rust nightly"
 rustup override set nightly
+echo "Update rust nightly"
+rustup update nightly
 echo "Downloading rust source"
 rustup component add rust-src
 if [ -z "$(which xargo)" ]