gb_sets and gb_trees: Add checks to from_ordset and from_orddict

[Maria-12648430]

I recently had the pleasure to debug some code where, ultimately, an unordered list and/or with duplicates, was given to gb_sets:from_ordset/1. The implementation does not complain, but silently turns the list into an invalid gb_set, resulting in misbehaviors like elements that are in the set not being found, and elements that have been deleted from the set still being reported as being in the set. Adding or deleting elements from the set may also result in elements appearing and disappearing. And so on 🤷‍♀️

This is a mistake easily made. Until recently, the documentation kinda encouraged the use of from_ordset in multiple places, with the assumption that the list given to it is sorted and free of duplicates only mentioned in the prose of from_ordset. It is also a mistake very hard to find once made, more so when you're not the person who wrote that code, and the person who did left years ago. (😡)

Anyway. This PR adds checks to the functions which turn lists-that-may-be-ordsets-or-not. Internal uses bypass the check in order to not impose a penalty when not necessary.

This also applies to gb_trees:from_orddict/1, which is likewise changed by this PR.

On the way, we also added gb_trees:from_list/1, and removed the one remaining old-style catch in sets_SUITE.

There are no tests yet, we would like to hear if this addition is really wanted or not before putting more work into it 😉

This change may break some existing code, but if so, IMO for the better, as it would clearly be a bug.

[github-actions]

CT Test Results

    2 files    100 suites   1h 3m 58s ⏱️
2 288 tests 2 237 ✅ 51 💤 0 ❌
2 707 runs  2 651 ✅ 56 💤 0 ❌

Results for commit 9e122bb.

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[bjorng]

Thanks for your pull request. It's looks good to me (except for one implementation detail), but we will have to discuss it in the OTP team.

[Maria-12648430]

Thanks for your pull request. It's looks good to me (except for one implementation detail), but we will have to discuss it in the OTP team.

Sure, no problem.

As it turns out, this change has already unearthed a bug in qlc_SUITE, btw.

[bjorng]

Thanks for your pull request.