New issue by Zapeth on void-packages repository

https://github.com/void-linux/void-packages/issues/43716

Description:
### Package name

rust-src

### Package homepage

https://github.com/rust-lang/rust

### Description

It looks like the [rust](https://github.com/void-linux/void-packages/blob/master/srcpkgs/rust/template) package is missing the std and core source files that would normally be required for language-servers to provide analysis (ie `rust-analyzer`).

I'm not sure what configuration steps would be necessary to provide the source files as a separate package, it seems it might be possible to include them in the build with the [`extended`](https://github.com/rust-lang/rust/blob/98c33e47a495fbd7b22bce9ce32f2815991bc414/config.example.toml#L293) and [`tools`](https://github.com/rust-lang/rust/blob/98c33e47a495fbd7b22bce9ce32f2815991bc414/config.example.toml#L303-L312) settings in the package `config.toml`.

Alpine also provides it as a separate package (https://pkgs.alpinelinux.org/package/v3.17/community/x86_64/rust-src), but I don't know how much can be gleaned from that, if anything.

Sidenote: `rust-analyzer` currently doesn't work out of the box with the `rust` package due to the missing sources, setting up this package and adding it as a dependency to `rust-analyzer` should hopefully fix that

### Does the requested package meet the package requirements?

Required

### Is the requested package released?

Yes