Display builtin aliases with cargo --list

[CPerezz]

As stated in #8486 it would help to the discovery of the
builtin aliases the facto of printing them with the
cargo --list command.

• Extracted the builtin aliases currently implemented to a
  separated const.
• Make all of the functions that interact with these aliases
  point to that function.
• Refactored the list_commands fn in order to include with the
  builtin and external commands, the builtin aliases that come with
  cargo by default.
• Added a test that checks that the aliases that currently
  are builtin with cargo are indeed being printed with the rest
  of the commands when cargo --list is called.

The output on my machine looks like this:

$ cargo --list
Installed Commands:
    b                    alias: build
    bench                Execute all benchmarks of a local package
    build                Compile a local package and all of its dependencies
    c                    alias: check
    check                Check a local package and all of its dependencies for errors
    clean                Remove artifacts that cargo has generated in the past
    doc                  Build a package's documentation
    fetch                Fetch dependencies of a package from the network
    fix                  Automatically fix lint warnings reported by rustc
    generate-lockfile    Generate the lockfile for a package
    git-checkout         This subcommand has been removed
    init                 Create a new cargo package in an existing directory
    install              Install a Rust binary. Default location is $HOME/.cargo/bin
    locate-project       Print a JSON representation of a Cargo.toml file's location
    login                Save an api token from the registry locally. If token is not specified, it will be read from stdin.
    metadata             Output the resolved dependencies of a package, the concrete used versions including overrides, in machine-readable format
    new                  Create a new cargo package at <path>
    owner                Manage the owners of a crate on the registry
    package              Assemble the local package into a distributable tarball
    pkgid                Print a fully qualified package specification
    publish              Upload a package to the registry
    r                    alias: run
    read-manifest        Print a JSON representation of a Cargo.toml manifest.
    run                  Run a binary or example of the local package
    rustc                Compile a package, and pass extra options to the compiler
    rustdoc              Build a package's documentation, using specified custom flags.
    search               Search packages in crates.io
    t                    alias: test
    test                 Execute all unit and integration tests and build examples of a local package
    tree                 Display a tree visualization of a dependency graph
    uninstall            Remove a Rust binary
    update               Update dependencies as recorded in the local lock file
    vendor               Vendor all dependencies for a project locally
    verify-project       Check correctness of crate manifest
    version              Show version information
    yank                 Remove a pushed crate from the index
    clippy
    clippy
    clippy
    clippy
    flamegraph
    fmt
    fmt
    fmt
    fmt
    miri
    miri
    miri
    miri
    outdated
    tree

As discussed with @ehuss the BTreeSet enforces Ord therefore, the aliases get mixed with the commands since they're passed through the same function.

It can be refactored to appear separately, but, the code will be more spread and now it's all in just one file (which I believe is easier to maintain and review).

Closes #8486

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @Eh2406 (or someone else) soon.

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[alexcrichton]

@bors: r+

Looks great to me, thanks @CPerezz!

[bors]

📌 Commit 7b16c7c has been approved by alexcrichton

[ehuss]

Instead of defining the set of aliases twice, perhaps just place them all in a single table? Like a 3-element tuple (alias, command, description), and then builtin_aliases_execs could just iterate over the array and find a match.

[CPerezz]

That's brilliant!! Will modify it!!

[alexcrichton]

@bors: r-

er, @ehuss has a good point!

[CPerezz]

I think this should do it. I'm considering to open a followup issue in respect to that and move all of the "aliased" stuff to a separate file so it's easier to upgrade on the future.

Suggestions are welcomed @alexcrichton @ehuss

[ehuss]

Thanks! 😄

@bors r+

[bors]

📌 Commit 2ae8df6 has been approved by ehuss

[bors]

⌛ Testing commit 2ae8df6 with merge 2d26633...

[bors]

☀️ Test successful - checks-actions
Approved by: ehuss
Pushing 2d26633 to master...

[ehuss]

@CPerezz I just noticed, I had intended for this to also include user aliases. Would you be willing to do a follow-up PR to add those, too?

[CPerezz]

Hi @ehuss sure! Feel free to open an issue and post your ideas there so I can take a look!

Also, could you please check #8640 since I'm also working on it and I'd need some help.

[ehuss]

Reopened #8486, let me know if you have any questions on it.