Fix parser warnings order

[omarjatoi]

See #11269 for more information. This PR changes the parse results to append warnings so they're displayed in-order.

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This PR modifies behaviour or interface

Include the following checklist in your PR:

• Patches conform to the coding conventions.
• Any changes that could be relevant to users have been recorded in the changelog.
  • Is the change significant? If so, remember to add significance: significant in the changelog file.
• The documentation has been updated, if necessary.
• Manual QA notes have been included.
• Tests have been added. (NOTE: I updated the ordering in existing test files)

[geekosaur]

Fine aside from the missing field in the changelog.

[omarjatoi]

Thanks! Let me get that fixed.

[geekosaur]

I do wonder if just doing a reverse at the end would be better, but on the other hand if they have enough warnings for that to make a significant difference then they have bigger problems than warning collection. 😁

[omarjatoi]

Yeah I thought of doing that at first, and figured it maybe made sense to just return the warnings in the correct order instead of having to reverse them. But I do not feel strongly, if that's preferred I'd be happy to make that change.

[geekosaur]

No, I don't think it's really necessary. The downside of xs ++ [x] is that it has to traverse xs, but again if they have that many warnings that this shows, they have bigger problems.