[Tracking] Documenting the Expected Undocumented Flags

Goal

This file contains many compiler flags that are undocumented. The goal is document every single one of them.

Building the docs

The source of the GHC users guide is found in the GHC repository in the docs/users_guide/ đirectory. In order to build it, please follow the first three steps listed at ghc.dev, and then run

$ hadrian/build _build/docs/html/users_guide/index.html

You will then find the index file at _build/docs/html/users_guide/index.html

Merge Requests Etiquette

When creating a merge request:

1. Insert this text at the bottom of the pull-request: Tracking: https://gitlab.haskell.org/ghc/ghc/-/issues/18641
2. Mention @core-libraries (by simply writing it out) at the end of the description. This will greatly help the review process.
3. Insert the ~documentation label. You can use the quick action /label ~documentation at the end of the MR's description when creating it for the first time;
4. Set the milestone to 9.0.1;

All those steps are important to ensure consistency in our efforts.