[fpc-pascal] Case statement for class introspection

[Ryan Joseph]

> On Jan 18, 2022, at 5:28 AM, Sven Barth <pascaldragon at googlemail.com> wrote:
> 
> The values will have the same differences between each other upon each start so ideally this would work anyway, but if one also throws dynamic packages into the mix things would get messed up. So better stay with the if-clauses.

Here's my issue and feature branch linked + tests. Please leave any comments since I wasn't 100% sure in a few places.

https://gitlab.com/freepascal.org/fpc/source/-/issues/39535

Now that the compiler is moved to GitLab do you prefer merge requests? I assumed no and that it would clutter up the system but I'll make a merge request if you want.

Regards,
	Ryan Joseph