On Linux (one that has a `js52`/`mozjs-52` package installed):
* Run `update-workspaces.sh` with the `--with-system-mozjs52` flag passed.
* Note the files (re)generated (e.g. `Generated ../workspaces/gcc/lobby.make`)
* Open one of the regenerated `*.make` files in a text editor
* Confirm that with the patch applied, `/usr/include/mozjs-52` is behind an `-idirafter`
* In the `gcc/obj` subfolder, remove the directory belonging to the regenerated file opened
* Going back a level (to `gcc`), run `make` (with `-j[n]` to taste)
* Confirm that it builds and links without issue.
On other systems:
* Make sure it builds and links with and without the `--with-system-mozjs52` flag (where applicable).