Fix Issue 20964

[9il]

[dlang-bot]

Thanks for your pull request, @9il!

Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	20964	blocker	poor CTFE support for backward pointer iteration

⚠️⚠️⚠️ Warnings ⚠️⚠️⚠️

• Regression or critical bug fixes should always target the stable branch. Learn more about rebasing to stable or the D release process.

To target stable perform these two steps:

1. Rebase your branch to upstream/stable:

git rebase --onto upstream/stable upstream/master

2. Change the base branch of your PR to stable

Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub run digger -- build "master + dmd#13096"

[UplinkCoder]

@9il for completeness sake you should also test a case in which the index would be out of bounds. to see what happens when that happens. I assume that nothing good will happen but you might be lucky and it's handled gracefully in the cases you are testing.

[nordlow]

No description provided.

I'm very happy to see your first dmd PR, @9il!

[9il]

I'm very happy to see your first dmd PR, @9il!

Man, it isn't first.

[nordlow]

I'm very happy to see your first dmd PR, @9il!

Man, it isn't first.

Ahh, sorry. Only searched your open PRs.

[RazvanN7]

@9il this seems to be failing the testsuite