Function bootstrap::compile::make_run_crates

pub(crate) fn make_run_crates(
    run: &RunConfig<'_>,
    alias: &str
) -> Interned<Vec<String>>

Given an alias selected by the Step and the paths passed on the command line, return a list of the crates that should be built.

Normally, people will pass just library if they pass it. But it’s possible (although strange) to pass something like library std core. Build all crates anyway, as if they hadn’t passed the other args.