tracking issue: distribution

[nrc]

Rust repo integration, rustup integration, etc.

• RLS should be able to pull down std libs info (or this should be automatically handled by rustup) (discussed in Easy to use indexing of std libs #88)
• run RLS tests in Rust CI (RLS tests are not being run rust#41199)
• --version (Implement ---version command line option #304, Dump pkg version & build date & commit hash if run with --version flag #308, Support rls --version rust#41197)
• Use in-tree version of Cargo when built inside Rust repo (RLS should use the in-tree copy of Cargo rust#41198)
• teach rustup about component dependencies
• add RLS to non-Rustup installers

cc @alexcrichton @brson

[nrc]

cc rust-lang/rust#41639

[Keruspe]

I think the last point was fixed by rust-lang/rust#42067