feat(cli/rustup-mode): warn about auto-installation in some subcommands#4895

rami3l wants to merge 3 commits into

rust-lang:release/1.29rust-lang/rustup:release/1.29from

rami3l:feat/backport-auto-install-rustup-warnrami3l/rustup:feat/backport-auto-install-rustup-warnCopy head branch name to clipboard